فهرست مطالب

  • سال شانزدهم شماره 4 (مهر و آبان 1398)
  • تاریخ انتشار: 1398/07/09
  • تعداد عناوین: 8
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  • پروانه بیک محمدلو، رسول یاراحمدی*، حسن اصیلیان، ازاده اشتری نژاد، مجید اسماعیلی صفحات 1-10
    زمینه و هدف

    هوای پاک به عنوان یکی از نیاز های اساسی برای سلامت و رفاه انسان مطرح می باشد. با این حال، به موازات رشد و توسعه اقتصادی، حمل و نقل، زندگی شهرنشینی و مصرف انرژی نیز افزایش یافته و نگرانی های زیادی از قبیل آلودگی هوا را فراهم نموده که نیازمند توجه فوری و گسترده است. منابع آلودگی هوا عمدتا شامل: ذرات معلق، ترکیبات آلی فرار، مونوکسید کربن، آمونیاک، اکسید گوگرد، دی اکسید کربن و غیره می باشند. در این میان، ترکیبات آلی فرار، بدلیل اثرات قابل توجه و جبران ناپذیر برسلامتی انسان و حجم بالای تولید، از مهمترین آلاینده های جوامع محسوب می شود. جذب سطحی از موثرترین روش های کنترلی و کربن فعال به عنوان یکی از پرکاربردترین جاذبهای مورد استفاده در این زمینه می باشد. از این رو هدف پژوهش حاضر، ایجاد تغییرات قابل توجه در ویژگی های ساختاری جاذب با بکارگیری روش پلاسما بعنوان تکنیک نوظهور دانش کنترل آلودگی هوا بمنظور افزایش کارایی آن تعیین گردیده است.

    روش بررسی

    در این تحقیق، ابتدا نمونه های گرانول کربن فعال توسط فرایند پلاسما متاثر از 4 متغیر: دما (°C40،70،100،130)، هواگذر جریان (Lpm75/0، 50/0، 25/0، 12/0)، زمان مواجهه با پلاسما (min 1،2،3،4) و ولتاژ مصرفی (kV 2/1 ،1 ،8/0 ،6/0) مورد اصلاح قرار گرفته شدند. سپس نمونه های گرانول کربن فعال اصلاح شده توسط بخار تولوئن در غلظت 200 ppm مورد جذب سطحی قرار گرفتند و زمان شکست جذب و ظرفیت جذب سطحی هر بستر بطور مجزا تعیین و محاسبه گردید. نمونه های با بیشترین ظرفیت جذب سطحی بمنظور بررسی سطح ویژه، قطر منافذ و مورفولوژی گرانول کربن فعال بعنوان مهمترین ویژگی های سطح جاذب، توسط آنالیز SEM و  BET مورد بررسی قرار گرفتند. همچنین به منظور تعیین ارتباط متغیر های فرایند اصلاح (دما، هواگذر، زمان مواجهه و ولتاژ مصرفی) با زمان شکست جذب و ظرفیت جذب سطحی، از آنالیز واریانس نرم افزار Minitab استفاده گردید.

    یافته ها

    نتایج نشان می دهد بعد از اصلاح در دمای °C130، هواگذر  75/0، زمان مواجهه min 1 و ولتاژ  1 بیشترین میزان ظرفیت جذب سطحی کربن فعال را خواهیم داشت که 56%  نسبت به جاذب اصلاح نشده افزایش یافته است. این در حالی است که اثر قابل توجهی در نتایج حاصل از تست های  (سطح ویژه، حجم مخصوص و قطر منافذ کربن فعال) مشاهده نشد و دلیل تغییرات جزئی مورد مشاهده نیز مربوط به تاثیر فرایند پلاسما روی سطح جاذب می باشد که منجر به تخریب و یا مسدود شدن برخی از منافذ گردیده است. ضمن اینکه تصاویر ، بیانگر تغییرات کمی در مقیاس میکرو و نانو روی سطح جاذب اصلاح شده نسبت به نمونه های اولیه می باشد.

    نتیجه گیری

    پلاسمای سرد، بعنوان روشی نوین و سازگار با محیط زیست منجر به ایجاد تغییرات فیزیکی و شیمیایی گرانول کربن فعال می گردد. که مهمترین دلیل افزایش ظرفیت جذب سطحی مربوط به تغییرات شیمیایی بوقوع پیوسته روی سطح جاذب، تحت تاثیر فرایند اصلاح می باشد.

    کلیدواژگان: پلاسما، ترکیبات آلی فرار، اصلاح، جذب سطحی، گرانول کربن فعال
  • حمزه محمدی، سمیه فرهنگ دهقان، محمد باقر عبدالهی*، مجتبی کلانتر، معصومه کایدانی صفحات 13-21
    زمینه و هدف

    تامین روشنایی مطلوب در محیط زندگی و کار جهت نمایان ساختن اشیاء و افزایش قدرت تمیز جزئیات و نیز پیشگیری از خستگی دیداری و خیرگی ضروری می باشد. بالا بودن میزان شدت روشنایی ناشی از منابع طبیعی و یا مصنوعی در برخی مشاغل می تواند به عنوان یک عامل زیان آور فیزیکی محسوب گردد. لذا این مطالعه با هدف بررسی اثرات سوء ناشی از مواجهه با میزان روشنایی با شدت بالا بر روی شاخص های اسپرم موش سوری انجام پذیرفت. 

    روش بررسی

    موش های سوری در دو گروه مواجهه (6=n؛ در معرض مواجهه با روشنایی با شدت 1000 لوکس طی 5 روز 8 ساعته) و شاهد (6=n؛ با شرایط مشابه ولی بدون مواجهه) بررسی گردیدند. در پایان سناریوی مواجهه، پس از بیهوشی حیوانات هر گروه با تزریق کتامین و زایلازین، ناحیه دم اپیدیدیم بیضه ها استخراج و جهت بررسی اسپرموگرام در محیط کشت ترکیبی قرار گرفتند. سپس ضمن تهیه قالب های پارافینی و برش های 5 میکرونی، سایرآزمایشات مربوط به شاخص های بافتی بر روی نمونه بیضه انجام شد. همچنین توسط میکروسکوپ نوری و با بزرگ نمایی 400  شمارش سلولهای اسپرماتوگونی، اسپرماتوسیت، اسپرماتید و اسپرم انجام گرفت. میانگین سه بار تکرار درون گروهی داده ها با سطح معنی داری 05/0 گزارش گردیدند. داده ها با استفاده از آزمون آنالیز واریانس یکطرفه و متعاقب آن، آزمون تعقیبی توکی تجزیه و تحلیل گردیدند.

    یافته ها

    اختلاف معنی داری در درصد تحرک کل اسپرم بین دو گروه (مواجهه: 96/0±7/60؛ شاهد: 02/1±4/72)، درصد مورفولوژی طبیعی اسپرم بین دو گروه (مواجهه: 58/3±50/45؛ شاهد: 6/1±35/73)، درصد زنده ماندن اسپرم بین دو گروه (مواجهه: 44/1±68/58؛ شاهد: 65/1±36/74)، و قطر داخلی لوله های اسپرم ساز بین دو گروه (مورد: 79/1±11/97؛ شاهد:02/1±82/66  میکرومتر) وجود داشت (05/0<p)؛ در حالیکه، اختلاف معنی داری در تعداد اسپرم برحسب میلیون بین دو گروه (مواجهه: 11/1±11/4؛ شاهد: 09/0±51/4) و قطر خارجی لوله های اسپرم ساز بین دو گروه (مواجهه: 95/1±27/160؛ شاهد: 33/1±89/161 میکرومتر) مشاهده نشد (05/0>p). تخریب بافتی، وجود بی نظمی، درهم تنیدگی و غیر نرمال بودن،  بهم ریختگی نظم سلول های اسپرماتوژن و تخلیه بخش میانی لوله های اسپرم ساز در گروه مواجهه در مقایسه با گروه کنترل مشاهده شد.

    نتیجه گیری

    مطابق یافته های پژوهش حاضر، مواجهه با روشنایی با شدت 1000 لوکس سبب کاهش در تحرک کل، درصد مورفولوژی طبیعی و درصد زنده ماندن اسپرم ها  شد که انتظار می رود این مقدار کاهش با گذشت زمان امکان ایجاد درجات مختلفی از ناباروری با فاکتور مردانه را افزایش دهد. همچنین افزایش در قطر داخلی لوله های اسپرم ساز ناشی از مواجهه با روشنایی 1000 لوکسی مشاهده گردید که حاکی از تمایز و مرگ سلولی در تعداد زیادی از سلولهای زایای رده های مختلف می باشد. باتوجه به اینکه مطالعات عمدتا بر شدت های پایین تر نور مرئی تمرکز داشته اند، به منظور نتیجه گیری قطعی لازم است مطالعات جامع تر بر گونه های حیوانی مختلف و در صورت امکان بر اسپرم های انسانی انجام شود.  از انجائیکه امروزه در مشاغل دقیق و نوبت کار مواجهه افراد با تابش های شدت بالا اتفاق می افتد، توصیه می شود به منظور پیشگیری از اثرات سوء احتمالی مواجهه با روشنایی شدت بالا، اقدامات کنترلی مقتضی در محیط های کاری انجام گیرد.

    کلیدواژگان: شدت روشنایی بالا، شاخص های اسپرم، ویژگی ریخت شناسی، موش سوری
  • محسن فلاحتی*، علی کریمی، مجتبی ذکایی، اعظم بیابانی، یوسف فقیه نیا ترشیزی، فرهاد صالحی صفحات 22-34

    با توسعه روزافزون استفاده از برق در تمامی جنبه های زندگی انسان، حوادث برقی نیز افزایش یافته است. یکی از مولفه های اصلی در مکانیزم پیشگیری از حوادث برقی، ارزیابی عملکرد ایمنی سازمان یا صنعت با استفاده از شاخص های ارزیابی عملکرد مناسب با عملیات مربوطه می باشد.

    روش بررسی

    این مطالعه، توصیفی-تحلیلی از نوع پیمایشی در 6 مرحله شامل : آنالیز ساختار شکست پروژه، آنالیز مقدماتی خطر عملیات، تشکیل شبکه علی حادثه، تعیین اقدامات کنترلی، استخراج شاخص های فعال ارزیابی عملکرد و اعتبارسنجی شاخص ها انجام گرفت.

    یافته ها

    در این مطالعه نرخ احتمال وقوع حادثه برق گرفتگی با استفاده از روش BN 053/0 بدست آمد و 11 شاخص فعال ارزیابی عملکرد ایمنی برق تدوین گردید. میزان R- square ضریب فراوانی حادثه با شاخص های فعال کل پروژه 819/0 و مقدار P-value کمتر از 05/0 بود. بنابراین این نتایج نشان می دهد همبستگی بین ضریب فراوانی حوادث بعنوان متغیر وابسته و شاخص های فعال بعنوان متغیرهای مستقل در کل پروژه معنادار می باشد.

    نتیجه گیری

     با پیشرفت عملیات در پروژه های عمرانی، سطح ریسک عملیات در این پروژه ها تغییر می کند.  بنابراین شاخص های اندازه گیری عملکرد ایمنی در این پروژه ها باید حساس به تغییرات سریع باشد. بنابراین شاخص های فعال که دارای دوره اندازه گیری کوتاه مدت می باشند جهت اندازه گیری سطح عملکرد ایمنی عملیات ساخت و ساز دارای اثربخشی بیشتر می باشند.

    کلیدواژگان: شبکه بیزی، Bow-tie، ایمنی برق، شاخص های ارزیابی عملکرد
  • عماد میر سلیمی، مسعود ریسمانچیان، سارا کریمی زوردگانی* صفحات 35-45
    مقدمه

    فلز سرب امروزه یکی از فلزات پر کاربرد در صنایع مختلف می باشد. این فلز یکی از عوامل بروز مشکلات و عوارض بهداشتی از جمله عوارض سیستم اعصاب مرکزی و کم خونی بوده که مواجهات شغلی و غیر شغلی را در بر دارد. با توجه به سمیت این فلز نیاز به بررسی مواجهات در محیط های مختلف می باشد از این رو این مطالعه با هدف تعیین میزان مواجهه کارگران با سرب  هوا  و تعیین سرب خون کارگران معدن تعریف گردید. در این تحقیق همچنین به منظور بررسی احتمال مواجهه پوستی سرب از مدل DREAM (Dermal exposure assessment Method)  استفاده گردید.

    روش ها

    مطالعه حاضر از نوع توصیفی- تحلیلی و به صورت مقطعی بوده که بر روی کارگران یک معدن سرب و روی با سابقه کار حداقل یک سال در استان اصفهان انجام گرفت. در این تحقیق میزان سرب در هوای منطقه تنفسی 46 نفر از این کارگران اندازه گیری گردید که از این تعداد، از 40 نفر نمونه گیری خون انجام گرفت. به منظور نمونه برداری و آنالیز نمونه های هوای منطقه تنفسی و خون کارگران جهت تعیین غلظت سرب به ترتیب از  استاندارد NIOSH7082 و NIOSH 8003 استفاده شد. به منظور بررسی میزان مواجهه پوستی کارگران از مدلی تحت عنوان DREAM استفاده شد که این مدل در مجموع 33 متغیر را شامل می شود. پس از جمع آوری داده ها نهایتا آنالیز آماری با استفاده از نرم افزار SPSS 22 و انجام آزمون های مربوطه  صورت گرفت.

     یافته ها

    بر اساس نتایج حاصل از این پژوهش میانگین سرب خون کارگران شاغل در تونل های معدن معادل  36/3 ±µg/dl 7/24 و میانگین غلظت سرب خون کارگران بیرون از تونل نیز معادل80/5 ±µg/dl 57/23 به دست آمد. میانگین سرب هوای منطقه تنفسی در داخل تونل ها معادل 015/0±  mg/m3 0205/0 و میانگین سرب هوای منطقه تنفسی در خارج از تونل ها برابر 017/0± mg/m3 0201/0 می باشد. نتایج آزمون T مستقل نشان داد که دو گروه عنوان شده از نظر میزان  سرب خون همگن نبوده و اختلاف معناداری بین میانگین سرب خون آنها وجود دارد (P<0.001). با توجه به نتایج آزمون همبستگی هیج ارتباط معناداری بین متغیرهای غلظت سرب هوای منطقه تنفسی و غلظت سرب خون با مواجهه پوستی حاصل از مدل DREAM  مشاهده نشد (به ترتیب با سطح معناداری 806/0 = Pv و 193/0 = Pv).

    نتیجه گیری

    طبق نتایج به دست آمده از این تحقیق محل کار پرسنل مهمترین عامل موثر در افزایش و کاهش سرب خون بوده و استفاده از وسایل حفاظت فردی مناسب، نحوه استفاده صحیح از آن ها، ایجاد برنامه زمان بندی مناسب بین حفاری و استخراج، استفاده از مالش های غیر نفتی جهت کاهش گرد و غبار های بعد از حفاری به منظور کنترل مواجهات با سرب توصیه گردید. همچنین پیشنهاد می گردد به منظور افزایش دقت در تعیین میزان سربی که از راه پوست وارد بدن می گردد از روش های نمونه برداری از سطح پوست و لباس نیز استفاده شود. همچنین ارزیابی ریسک های مواجهات شغلی به منظور تعیین محل کار کارگران با کمترین  و بیشترین سسطح ربسک نیز پیشنهاد گردید.

    کلیدواژگان: سرب، پایش هوا، پایش بیولوژیکی، مدل DREAM
  • ویدا زراوشانی*، علی صفری واریانی، سعید احمدی صفحات 46-58
    زمینه و هدف

    مواجهه شغلی با پرتوهای راداری دارای اثرات زیانبار حرارتی و غیر حرارتی متفاوتی است. با توجه به اهمیت شناخت ریسک فاکتورهای شغلی سرطانزا در پیشگیری و کاهش هرینه ها و نیز نبود مطالعات مشابه، این مطالعه با هدف مرور نظام مند پژوهش های انجام شده در رابطه با ریسک ابتلا به سرطان در مواجهه های شغلی با پرتوهای راداری (با فرکانس 1 تا 3000 گیگاهرتز) انجام شد.

    روش بررسی

      جستجوی نظام مند بر اساس روش PRISMA و در محدوده زمانی مارس 2017 تا سپتامبر 2018 و در پایگاه های Sid ،Magiran  Google Scholar,،PubMed ، Scopus و ISI Web of Science Database انجام شد و مقالات انگلیسی و فارسی زبان و بدون محدودیت زمانی بررسی شدند.کلیدواژه ها بر اساس اصل PICO و با استفاده از پایگاه MeSH انتخاب گردیدند. سپس با در نظر گرفتن معیارهای ورود و خروج، فرایند مرور، غربال گری و حذف اطلاعات تکراری ، غیرمرتبط انجام شد. علاوه بر این بازیابی مجدد منابع انجام و پس از تهیه متن کامل مقالات ورودی ، استخراج داده ها انجام شد.

    یافته ها

    در جستجوهای اولیه در مجموع 533 مطالعه یافت شد که همگی از پایگاه های خارجی بودند. در این فرایند، مطالعه کارآزمایی بالینی و مطالعات فارسی مرتبط یافت نشد. بر اساس معیارهای ورود و خروج ، در نهایت تعداد 7 مقاله (4 مطالعه کوهورت و 3 مطالعه مورد-شاهدی) وارد این مرور سیستماتیک شدند .مطالعات ورودی در طی سال های  1950تا 2005 و با 51898 نمونه انجام شده و در بازه زمانی 1993 تا 2016 منتشر شده بودند . بیشتر مطالعات در خصوص سرطان بیضه و سرطان مغز صورت گرفته بود. در مطالعات ورودی ، برآورد خطر نسبی صرفا در خصوص سرطانهای بیضه، لوسمی و مغز انجام و برآورد نرخ مرگ و میر در طیف وسیعی از سرطانها گزارش گردیده بود. این مطالعات افزایش نرخ مرگ و میر ناشی از سرطان بیضه را غیر معنی دار اعلام نمودند اما افزایش خطر نسبی آن را در دو مورد معنی دار گزارش کرده بودند. همچنین افزایش نرخ مرگ و میر ناشی از ابتلا به سرطان مغز در میان کارکنان تحت مواجهه ، در دو مطالعه معنی دار گزارش گردید. در حالیکه افزایش خطر نسبی ابتلا به این سرطان در کارکنانی که با پرتوهای راداری مواجهه شغلی داشتند معنی دار اعلام شده بود.

    نتیجه گیری

    با توجه به اینکه پژوهش حاضر جزء اولین مطالعات مروری است که در زمینه تاثیر مواجهه شغلی با پرتوهای راداری بر ریسک ابتلا به سرطان انجام شده لذا نتایج این مطالعه می تواند در سیاستگذاری سلامت در زمینه بهداشت پرتوهای غیریونیزان (متمرکز بر پرتوهای راداری) برای سازمانهای فعال در این زمینه و نیز تمامی محیط های کاری که کارکنان آنها با این دسته از پرتوها موجهه شغلی دارند مفید باشد و بخشی از اطلاعات مورد نیاز برای انجام یک مطالعه متاآنالیز مرتبط در آینده را تامین نماید. با توجه به محدودیت مطالعات ورودی، ادامه تحقیقات تجربی روی انسانها با گروه های شاهد و با تمرکز بر بررسی سرطانزایی پرتوهای راداری در مواجهه شغلی کارکنان  امری ضروری به نظر می رسد. همچنین پیشنهاد می شود در مطالعات به از مقالات منتشره در همایشها و کنگره ها نیز استفاده شده و محدودیت زبان چاپ مقاله در فرایند جستجو برداشته شود.

    کلیدواژگان: مواجهه شغلی، سرطان شغلی، پرتوهای راداری، مرور نظام مند
  • احمد سلطانزاده، حمیدرضا حیدری*، شهرام ارسنگ، لیلا اندرزخورا، فاطمه هوشیار، مریم محمودی، هدی رحیمی فرد صفحات 59-71
    زمینه و هدف

    دسترسی به ابعاد آنتروپومتریکی هر جامعه امری ضروری در طراحی تجهیزات می باشد. علیرغم اعتبار و دقت بالای وسایل و روش های مستقیم سنجش ابعاد آنتروپومتری، بدلیل محدودیتهای کاربرد این نوع روش ها بویژه در محیط های شغلی استفاده از روش های غیر مستقیم اهمیت ویژه ای پیدا نموده است. در این راستا، توجه به روابط بیومتریک ابعاد بدنی می تواند مفید واقع گردد. چرا که در صورت یافتن رابطه معنی دار بین یک یا چند بعد آنتروپومتری با سایر ابعاد بدنی می توان با صرف زمان و هزینه اندک و بدون نیاز به تخصص خاص، ویژگی های آنتروپومتریک مورد نیاز افراد را در محیط های کار با درجه اطمینان بالایی برآورد نمود. از اینرو این مطالعه به بررسی رابطه رگرسیونی بین ابعاد مختلف نسبت به قد افراد در یک جمعیت مشخص می پردازد.

    روش بررسی

    در این مطالعه 206 نفر از دانشجویان در گستره سنی 18 تا 26 سال مورد بررسی قرار گرفتند. ابعاد مورد سنجش در این مطالعه شامل 20 بعد در وضعیت ایستاده و 18 بعد در وضعیت نشسته بودند. برای سنجش افراد از وسایل سنجش مستقیم همچون آنتروپومتر، کالیپر، کولیس و متر نواری استفاده گردید. نتایج مطالعه با استفاده از نرم افزار SPSS 22 مورد تجزیه و تحلیل قرار گرفت. بطوری که با استفاده از شاخص های پراکندگی و صدک های 5، 50 و 95، همچنین میانگین و انحراف معیار، توزیع داده های آنتروپومتری مورد بررسی نشان داده شد.  همچنین به منظور بررسی روابط بیومتریک ابعاد مختلف نسبت به قد افراد در جمعیت مورد مطالعه از مدل های رگرسیون چندگانه خطی استفاده گردید. در این مدلها، رابطه بیومتریک ابعاد مختلف بدن بر اساس بعد قد که به سادگی سنجش آنها امکان پذیر بود در وضعیت های استاتیکی نشسته و ایستاده مورد بررسی قرار گرفت.

    یافته ها

    بطور کلی  مقادیر اغلب داده های آنتروپومتریک مورد سنجش در خانم ها کوچکتر از آقایان بوده است (05/0<p). در فاصله اطمینان 95% در بین زنان، چنگش ایستاده، طول اندام فوقانی و ارتفاع آرنج به ترتیب با داشتن ضرایب همبستگی 791/0، 742/0 و 737/0 بیشترین تناسب را با بعد قد نشان داده اند و سایر ابعاد همبستگی متوسط و ضعیفی با بعد قد داشته اند. در مردان ارتفاع شانه، ارتفاع چشم و طول اندام فوقانی به ترتیب با ضریب همبستگی 944/0، 867/0 و 840/0 بیشترین ارتباط را با بعد قد نشان داده اند. بطور کلی 12 معادله رگرسیونی برای ابعاد ایستاده نسبت به قد در بین زنان و 14 معادله رگرسیونی برای ابعاد ایستاده نسبت به قد در بین مردان حاصل گردید. مقادیر متناظر آن برای ابعاد نشسته به ترتیب برای زنان و مردان 14 و 12 معادله رگرسیونی بوده است.

    نتیجه گیری

    با توجه به محدودیتهای سنجش ابعاد آنتروپومتریک در هنگام طراحی، استفاده از روابط بیومتریک می تواند بعنوان یک روش غیر مستقیم عملی، سریع و جایگزین قابل قبول پیشنهاد گردد. بر اساس نتایج این مطالعه، می توان بعد قد را به عنوان یک بعد شاخص و پیش بینی کننده مناسب در طراحی های مبتنی بر داشتن ابعادی همچون ارتفاع شانه، ارتفاع چشم و طول اندام فوقانی،  چنگش ایستاده، طول اندام فوقانی و ارتفاع آرنج معرفی نمود.

    کلیدواژگان: آنتروپومتری، ابعاد استاتیکی، رگرسیون، پیش بینی، ارتباط، قد
  • سید مهدی موسوی، روح الدین مرادی راد، محمد حسین بهشتی، روح الله حاجی زاده*، فرشته طاهری، اسماعیل خداپرست، سعید یزدانی راد، یوسف فقیه نیا ترشیزی صفحات 72-82
    زمینه و هدف

    مواجهه با صدا خطر شغلی معمول در گستره وسیعی از محیط های کاری بخصوص صنایع نفت و گاز و شرکت های مرتبط محسوب می شود. این مطالعه در سال 1394 و با هدف ارزیابی صدای محیطی قبل و بعد از انجام اقدامات اصلاحی در 11 واحد عملیاتی بخش مخازن و نقل و انتقال مواد نفتی شرکت پالایش نفت آبادان صورت گرفت.

    روش کار

    در ابتدای پژوهش اطلاعات اولیه شامل محل استقرار منابع صوتی و شرایط عملیاتی تجهیزات جمع آوری شد. اندازه گیری صدا بر اساس استاندارد ISO 9612 به روش شبکه بندی قبل و بعد از انجام اقدامات اصلاحی شامل تعمیر و یا تعویض قطعات معیوب و فرسوده و یا روغنکاری قطعات متحرک و  با استفاده از صدا سنج مدل SLM CEL490 و مدل کالیبراتور CEL-110/1 ساخت شرکت casella انجام شد .

    یافته ها

    بر اساس نتایج  این مطالعه واحد NTA  دارای بیشترین میزان آلودگی صوتی (97دسی بل) و واحد مخازن کروی دارای کمترین میزان آلودگی صوتی (82  دسی بل) بود. از کل 523 ایستگاه اندازه گیری شده در این مطالعه 115 ایستگاه دارای تراز فشار صوت بیش از 85 دسی بل ، 373 ایستگاه دارای تراز فشار صوت بین 65 تا 85 دسی بل و 30 ایستگاه دارای تراز فشار صوت کمتر از 65 دسی بل است. نتایج اندازه گیری بعد از انجام اقدامات اصلاحی نشان داد که واحد تلمبه خانه نفت 1 به میزان 39/2دسی بل،  واحد کنترل سنتر به میزان 7/1 دسی بل، واحد تلمبه خانه نفت چرک 0.98دسی بل واحد NTA به میزان 08/0 دسی بل کاهش تراز فشارصوت میانگین داشته اند.

    نتیجه گیری

    اندازه گیری های محیطی صدا نشان داد که واحد NTA یکی از حادترین شرایط را از دیدگاه آلودگی صوتی در بین واحدهای دیگر دارا می باشد. این مطالب موید ضرورت شناسایی منابع اصلی صداساز و اولویت بندی بخش های مختلف این واحد صنعتی جهت اجرای طرح های کنترل مهندسی آلودگی می باشد.

    کلیدواژگان: آلودگی صوتی، کنترل صدا، اندازه گیری صدا، شرکت نفت
  • مرتضی آقاحسنی، عابدین ثقفی پور، معصومه معصومه فرشیدمقدم، مریم خاکبازان، ابوالفضل محمدبیگی*، سمانه ابوالخیریان صفحات 83-95
    زمینه و هدف

    ارتقای سطح سلامت و پاسخ گفتن عادلانه به نیازهای بهداشتی مردم و جوامع مهمترین ماموریت نظام سلامت هر کشور به شمار می رود. در سال های اخیر از سویی مفهوم سلامت و تعیین کننده های آن و از سویی دیگر نیازهای بهداشتی و ساختار جمعیتی جوامع دستخوش تغییرات زیادی شده است . دسترسی عادلانه به خدمات بهداشتی با کیفیت بدون توجه به تدوین استراتژی ها و برنامه ریزی های مناسب و نیز  بهره گیری از اصول مدیریت منابع انسانی امری ناممکن بنظر می رسد . به عبارت بهتر ایجاد تعادل بین نیروی انسانی و بارکاری کارکنان سلامت شاغل در مناطق مختلف از جمله مناطق حاشیه شهر ها که ساختار جمعیتی و نیاز های متفاوتی در مقایسه با جمعیت شهری دارند از الزامات مدیریت در حوزه سلامت می باشد. این مطالعه به منظور مقایسه زمان سنجی مراقبت های بهداشتی اولیه و بار کاری کارکنان شاغل در پایگاه جامع سلامت حاشیه شهر و بافت شهری استان قم، طراحی و اجرا گردید.

    روش بررسی

    این پژوهش بصورت مقطعی- تحلیلی در نیمه دوم سال 1396 به روش تصادفی از بین پایگاه های مستقر در دو پایگاه حاشیه شهر و دو پایگاه بافت شهری قم انجام شد. در یک مقطع زمانی 3 ماهه، 1000 نفر-مراقبت در مادران باردار و گروه های سنی مختلف دریافت کننده مراقبت بهداشتی در پایگاه های جامع سلامت، زمان سنجی شد. مراقبت ها توسط 4 نفر از مراقبین سلامت که از نظر سرعت و کیفت کار مشابه هم بودند، انجام شد و زمان سنجی خدمات و بارکاری آنها با روش Stop Watchبا دو کرونومتر از طریق مشاهده مستقیم ناظر، اندازه گیری شد. تجزیه و تحلیل داده ها بوسیله آزمون تی مستقل انجام گردید.

    یافته ها

    در این مطالعه،میانگین زمان کلی مراقبت در مراقبتهای پیش از بارداری 6 ±23دقیقه بود. همچنین مراقبت های بارداری با میانگین کلی5/9 ± 35 دقیقه بیشترین زمان را به خود اختصاص داد.در حالی که نتایج بدست آمده از زمان سنجی سایر مراقبت های ارائه شده در بسته مراقبت های طرح تحول سلامت نشان داد میانگین زمان کلی برای مراقبت های نوزادان وکودکان به ترتیب 5±7/24 و6±22 دقیقه و در مورد مراقبت های میانسالان زن و سالمندان5/4 ± 5/26و 9±33 دقیقه بود. همچنین نتایج این مطالعه اختلاف معناداری را بین زمانبری این مراقبت ها درپایگاه های سلامت حاشیه شهر و پایگاه های سلامت بافت شهری نشان داد (05/0> p). به علاوه، میانگین کلی زمانبری برای مراقبت های پس از زایمان و باروری سالم به ترتیب 5±20و8/2± 4/7 دقیقه و برای مراقبت های نوجوانان و جوانان و نیز میانسالان مرد به ترتیب 8/5±5/32و4/6±24و 9±31 دقیقه بودکه اختلاف معناداری را میان پایگاه های سلامت حاشیه شهر و بافت شهری نشان نداد (05/0< p).

    نتیجه گیری

    تفاوت در زمان سنجی خدمات بهداشتی و بارکاری درپایگاه های سلامت حاشیه شهر و بافت شهری می تواند در برنامه ریزی و تعیین تعداد نیروی انسانی متناسب با نوع خدمت، محل خدمت و نیازهای گروه های هدف در ارایه مراقبت های باکیفیت و مناسب، با رعایت اصول مدیریت منابع انسانی مورد استفاده قرار گیرد.به عبارتی دیگر، دسترسی عادلانه تر به مراقبت های بهداشتی اولیه،نیازمند توجه بیشتر برنامه ریزان و سیاست گزاران به تفاوت های جمعیت شناختی و نیازهای مناطق مختلف بافت های شهری و حاشیه ای است.

    کلیدواژگان: بارکاری، مدیریت زمان، خدمات بهداشتی اولیه، طرح تحول سلامت
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  • Parvane Beykmohamadloo, Rasoul Yarahmadi*, Hassan Asilyan, Azadeh Ashtarinezhad, Majied Esmaeili Pages 1-10
    Background and aims

    Clean air is one of the basic needs for human health and well-being. However, along with economic growth and development, transportation, urbanization and energy consumption have also risen and provide many concerns such as air pollution, which require urgent and wide attention. Air pollution in the worldwide is considered as a risk factor for human health and one of the main challenges of modern countries. In this regard, the organizations responsible in different countries, determine the rules of the threshold limit values of pollutants such as: carbon monoxide, nitrogen oxides, sulfur compounds, heavy metals, volatile organic compounds and propose solutions for their control. Air pollution sources are mainly composed of: suspended particles, volatile organic compounds, carbon monoxide, ammonia, sulfur oxides, carbon dioxide. Meanwhile, volatile organic compounds are one of the most important pollutants in communities due to their significant and irreparable effects on human health and high production. These compounds have been rejected due to the destruction of the stratospheric ozone, photochemical oxidant precursors, acid rain, climate change and global warming, effects on the nervous system, cancer, and so on. In order to eliminate and control these emissions, several methods have been identified such as catalytic and thermal oxidation, condensation, biological, membrane separation, absorption and adsorption. The methods mentioned each for different reasons and functional characteristics have their strengths and weaknesses in utilizing air purification technologies. However, adsorption is one of the most effective control methods and activated carbon as a porous and non-polar adsorbent is one of the most widely used adsorbents due to its hydrophobicity, high surface area, high adsorption capacity and relatively cheap price in this field.  In spite of the proper efficiency of activated carbon in the adsorption of pollutants, especially for volatile organic compounds, attempts to improve the adsorption capacity of activated carbon by various methods are being carried out with researchers. Conventional modification methods for increasing the adsorption capacity of activated carbon, includes: chemical methods (acid treatment, base treatment), modification by impregnation, physical methods (thermal methods, oxidation,) biological methods, ozone, plasma (dielectric barrier discharge plasma), microwave, and so on. In recent years, the use of plasma has increased significantly in order to modification of surface of various types of materials and compared with other conventional technologies in the field of modification of surfaces, as a promising method, in a shorter and easier time. In addition, there are no secondary pollutants in it. Plasma is ionized gas that all or a significant portion of its atoms have lost one or more electrons and have become positive ions. Types of non-thermal plasma includes: corona discharge, DBD (dielectric barrier discharge), glow discharge, microwave discharge, gilding arc discharge etc. In fact, this method is very efficient and easy to modification of surfaces, and by making physical and chemical changes in the surface structure of materials, the surfaces are modified. Physical changes are mainly caused by UV radiation and other radiation emitted from the discharge to surface, production of active particles such as ions, free radicals and ozone gas and usually affect the porous structure of the adsorbent in order to increase the adsorption capacity.Proper physicochemical background and widespread use of activated carbon in the removal of air pollutants (especially volatile organic compounds) have led to special attention being paid to altering the structural and chemical properties of these adsorbents using other existing techniques and emerging techniques of air pollution control knowledge by various scientists and researchers. Therefore, the purpose of this study was to make significant changes in the structural properties of the adsorbent by using the plasma method as the newest techniques of air pollution control knowledge in order to increase the adsorption capacity and efficiency of adsorbent.

    Methods

    Merck's activated carbon granule with mesh 12 as an adsorbent and Merck's toluene with 99.9% purity were used as pollutant. This study was conducted in two separate parts. The first part is related to the plasma modification process, which were affected by four variables: temperature (40, 70, 100, 130 ℃), flow rate (0.12, 0.25, 0.50, 0.75 ), exposure time with plasma (1, 2, 3, 4 min) and voltage (0.6, 0.8, 1, 1.2 ). Modification setup includes of high voltage power supply (alternating current), cylindrical DBD reactor as 1 mm thickness, anode and cathode respectively of foil cooper and stainless steel, respectively plus two multimeters separately (for simultaneous reading of ampere and voltage). In the second section, the modified activated carbon granule samples were adsorbed with toluene vapors at a concentration of 200 ppm. The measurement of the toluene vapor concentration was also performed by direct reading using a Phocheck based on photo ionization detector. The breakthrough time and adsorption capacity of each activated carbon granule beds were determined and calculated separately. Activated carbon granule beds with the highest breakthrough time and adsorption capacity were investigated with  and  analysis for the specific surface area, porosity diameter and morphology of activated carbon granules as the most important adsorbent properties. Analysis of variance of Minitab software was also used to determine the correlation between variables of the modification process (temperature, flow rate, exposure time with plasma and voltage) with breakthrough time and adsorption capacity.

    Results

    The results show that, the maximum breakthrough time and adsorption capacity of modified activated carbon granules are in 130℃ temperature, 0.75  flow rate, 1 min exposure time with plasma and 1  voltage. In these conditions of modification, 56% increase in adsorption capacity was observed in comparison with the unmodified activated carbon granule. However, there was no significant effect on the results of BET tests (in order to study of the specific surface area, total pore volume and mean pore diameter) and the reason for the slight changes observed is the effect of the plasma process on the adsorbent surface, which has resulted in the destruction or blockage of some pores. Meanwhile, Fe-SEM images (with a magnification of 30, 5000, and 150,000) indicate the slight change in the micro and nano scales on the modified activated carbon surfaces in comparison with the unmodified activated carbon surface. In fact, the surfaces of activated carbon granules exposed to dielectric barrier discharge plasma is better in terms of the presence of waste and pollutants on the surface than the unmodified activated carbon. The reason for the decrease in adsorption capacity in some beds can also be due to the high voltage during prolonged exposure which results in degradation of pores and active molecules on the adsorbent surface. However, sometimes increasing the functional groups on the surface of the adsorbent can lead to clogging of pores and a decrease in the specific surface area and ultimately decrease the adsorption capacity. Among the variables of the modification process, except for the temperature, no significant correlation was found between the variables (flow rete, exposure time with plasma, voltage) and the adsorption capacity of the modified activated carbon samples, and only the temperature variable showed a significant level of P-value. Some studies have similar results in this regard. In one study, after survey of the orange acid adsorption in aqueous solution by plasma-modified activated carbon fibers, they reported that the modification process resulted in a decrease in the specific activated carbon level and the increased adsorption capacity of orange acid was attributed to the increase in functional groups. In another study of mercury removal through adsorption on activated carbon modified with plasma, a slight decrease in size and total volume of pores, a slight increase in the mean diameter and specific surface area of meso and macro pores, the increase of the oxygen-containing functional groups, increases in the active sites related to chemical adsorption on the adsorbent surface and finally increase in adsorption capacity were reported.

    Conclusion

    Based on the results obtained and as well the results of other studies, the reason for increasing the adsorption capacity of toluene vapors on the activated carbon granule, despite the reduction of the structural properties of the activated carbon after modification, can be attributed to changes in the chemical properties of the adsorbent surface (functional groups), which requires further studies in this regard to confirm its accuracy. Generally, plasma as a novel and eco-friendly method, by making changes in the chemical and physical properties of activated carbon granule, leads to an increase in the adsorption capacity of toluene vapors. The most important reason for increasing adsorption capacity attributed to chemical changes on the adsorbent surface affected by the modification process.
    Keywords: Plasma, volatile organic compounds, modification, adsorption, activated carbon granule

    Keywords: Plasma, volatile organic compounds, modification, adsorption, activated carbon granule
  • Hamzeh Mohammadi, Somayeh Farhang Dehghan, Mohammad Bagher Abdollahi*, Mojtaba Kalantar, Masomeh Kaydany Pages 13-21
    Background and aims

    High light level of natural or artificial sources in some workplaces may be considered as a hazardous physical agent. The present study aimed to assess the effect of light level of 1000 lux on sperm parameters  in mice.

    Methods

     The subjects were assessed in two group including 1. Exposed (n= 6; exposed to light level of 1000 lux during 5 eight-hour days), 2. Unexposed or control (n= 6; similar condition, but without exposure). At the end of the exposure scenario, first they were anesthetized intramuscularly with ketamine and xylazine, then Testicular Extract was done and to study spermogram, samples which were putted in culture medium. Finally, Paraffin molds and 5-micron slices were provided and all tests related to tissue index were performed on the samples. The mean three-time intra-group replication of the data with a significant level of 0.05 was reported. Data were analyzed by one-way ANOVA and Tukey's post hoc tests.

    Results

    There was a significant difference in total sperm motility between two groups (exposed: 60.7% ± 0.96; control: 72.4 %± 1.02), percentage of sperms with normal morphology (exposed: 45.5 ± 3.85; control: 73.35 ± 1.6), percentage of survival of sperm (exposed: 58.68 ± 1.44; control: 74.36 ± 1.65), and internal diameter of the spermatozoa tubes (exposed: 97.11 μm ± 1.79; control: 66.82 μm ± 1.22) (P <0.05). No significant difference in the number of sperm in millions (exposed: 11.11 ± 1.11; control: 4.51 ± 0.09) and external diameter of the spermatozoa tubes (exposed: 160.27 μm ± 1.95; control: 161.89 ± 1.33 μm) was observed between the two groups (P> 0.05).

    Conclusion

    According to our findings, exposure to the light level of 1000 lux may reduce total motility, natural morphology percentage and survival rate of sperms, which is expected to increase with the possibility of different degrees of infertility with male factor over time. There was also an increase in the internal diameter of the sperm membranes due to the exposure to 1000 lux, indicating cell differentiation and death in a large number of different germ cells.

    Keywords: High light level, sperm index, morphological characteristics, mice
  • Mohsen Falahati*, Ali Karimi, Mojtaba Zokaie, Azam Biabani, Yoosef Faghihnia Torshizi, Farhad Salehi Pages 22-34
    Background

    With the developing use of electricity in all aspects of human life, electricity accidents have also increased. One of the main components of the for the prevention policy, is the safety performance assessment of the organization's or industry's by using appropriate performance indicators with related operations.

    Method

    This study was a descriptive-analytical of 6 steps including: analysis of work Breakdown Structure of the project, preliminary hazard analysis of the operation, the establishing of the accident causal network, determination of control measures, extraction of active performance indicators and validation of the indicators.

    Results

    In this study, the probability of occurrence of electric shock was 0.053 calculated using the method of BN and 11 active performance indicators were developed. The R-square value of the incident frequency with the active indicators of the total project was 0.819 and P-value was less than 0.05. Therefore, these results indicate that the correlation between incident frequency as an associated variable and active indicators as independent variables in the whole project is significant.

    Conclusion

    As the project progresses, the nature and level of risk of the operation of construction projects is changing. Therefore, indicators of safety performance measurements in these projects should be sensitive to rapid changes. For this reason, active indicators with a short-term measurement period are more effective in measuring the safety performance of construction operations.

    Keywords: Bayesian network, Bow-tie, Electrical Safety, Active performance indicators
  • Emad Mirsalimi, Masoud Rismanchian, Sara Karimi Zeverdegani* Pages 35-45
    Background and aim

    Lead is ubiquitous and one of the earliest metals discovered by the human. This metal is widely used in different industries due to its important physico-chemical properties like softness, high malleability, ductility, low melting point and resistance to corrosion. Lead absorbed in body with several routs and when transfer in blood is primarily in red blood cells. Human exposure to this toxic metal and its compounds occurs mostly in lead related occupations and also non-occupational exposures can acccure. Lead and lead compounds are not beneficial or necessary for human health, and can be harmful to the human body.The health effects of lead are directly related to the concentration of lead in the affected organe. Lead can affect on various organs in the body and it is one of the causes of problems and health conditions, including effects on central nervous system and cuses anemia, abnormal behavior, depression, nausea, fatigue, Lead colic, high blood pressure, joint and muscle pain and headache. Also researchs show that Lead causes other health problems such as toxicity of the liver and kidneys system. Initial symptoms of lead poisoning are non-specific and some factors such as age, the amount of lead, whether the exposure is over a short-term or a longer period will influence what symptoms or health effects are exhibited. Due to the toxicity of this metal, it is necessary to investigate exposures of this toxic heavy metal in different environments. Lead exposure at mines is a concern therefore to determine the concentration of lead in air and blood samples of miners; air and blood sampling were down with specific methods. Another part of the study was the estimate of miners skin exposure that for this porpuse, DREAM (Dermal exposure assessment method) model was used.

    Methods

    This study is a cross-sectional, descriptive-analytic research that was conducted on workers of a lead and zinc mine in Isfahan province. This research includes workers with at least one year of work experience. The oncentration of lead in the respiratory air of 46 workers was measured and of these, 40 blood samples were taken. In order to sampling and analysis of respiratory air samples, NIOSH7082 method was used that in this method for Lead sampleing the cellulose ester membrane filter was fitted into a holder and the calibrated individual sampling pump with a flow rate of 2 liters per minute was connected to the filter holder. After completion of the sampling, analysis was carried out using an atomic absorption spectrophotometere, flame. Biological monitoring of lead was performed on the basis of NIOSH8003 method after obtaining informed consent from the personnel and a complete explanation of the sampling steps. After collecting blood samples and preparing of them, analysis was performed using atomic absorption device. At the other stage of the research after extracting work information, the DREAM model was designed by the authors in Excel 2016 software. DREAM model, consists of an inventory and an evaluation part so the inventory part comprises a questionnaire with some modules consist of  exposure, department(the observer indicates whether exposure to chemical or biological substances is likely to occur), company(general information on the company), job(job titles are defined and information on workers’ hygiene is obtained), agent( physical and chemical properties of substances are collected) and task(information is obtained on frequency and duration of task performance). Key items of the exposure module are assessment of probability and intensity of three dermal exposure routes: emission, deposition and transfer. Emission involves mass transport of substances by direct release from a source onto skin or clothing, deposition on skin or clothing describes mass transport from air, ransfer is defined as the transport of mass from contaminated surfaces onto skin or clothing. In DREAM model, exposure assessment for nine different body parts takes place at the task level to assessing both potential dermal exposure(Skin-PTASKBP) and actual dermal exposure(Skin-ATASK.BP). Potential dermal exposure is defined as exposure on clothing and uncovered skin, whereas actual dermal exposure is about exposure on skin. The potential exposure estimate (Skin-PBP) for a certain body part comprises the sum of dermal exposures due to three different exposure routes: emission (EBP), transfer (TBP) and deposition (DBP).  Finally after collecting data statistical analysis of the data was performed using SPSS 22 software and related statistical tests.

    Results

    In this research the average age of mining workers is 35.5 years, the average weight is 51.72 kg and the mean of height is 172.54 cm. According to the results of this study, mean blood lead in different age groups is not the same so that the level of blood leads in the age group of 22 to 38 years old was lower than the age group of 39 to 53years. The results of this study showed that the average blood lead of workers in mining tunnels was 24.7μg/dl ±3.36 and the average blood lead concentration of workers outside the tunnel was 23.57μg/dl ± 5.80. The mean air lead of the respiratory region within the tunnels is 0.0205 ± 0.015 mg/m3 and the mean air lead of the respiratory air region outside the tunnels is 0.0201 ± 0.017 mg /m3. Independent T-test showed that workers were not homogeneous in terms of blood lead variable and there was a significant difference between the mean of blood lead (P <0.001). Results show that although, with increasing work history, the level of blood lead in individuals has increased, but this increase is not statistically significant (P = 0.224). Comparison of the results obtained from the control and main samples showed that the mean and standard deviation of blood lead in the main and control samples are 24.5±5.43 and 17.08± 3.85 respectively. According to the results of the correlation test, there was no significant correlation between the Lead concentration of the respiratory air region, the concentration of leed in blood samples and the actual skin exposure that comes with the DREAM model with a significant level of Pvalue = 0.806 and Pvalue = 0.193, respectively. The mean of lead concentration in respiratory air was compared with occupational exposure limit in Iran so that the average results of the respiratory air lead were 0.02 mg / m3, which is less than the limit specified. According to the results of this study, the mean blood lead of workers was 24.5 μg/dl, which is less than biological exposure indices. DREAM model analysis show that 15.2% of miners had a low exposure rating with lead, 4.3% ranked average, 13% high, 37% very high and 30.4% had very high exposure rating.

    Conclusion

    Regarding the porpuse of this study, after careful observation of the process and the different sections and working areas, the level of Lead in the blood respiratory air were measured and analyzed. According to the results of this research workplaces are the most important factor in increasing and reducing blood lead. It is almost impossible to remove lead completely from the human body; therefore reduction and prevention of lead exposure are very important. The use of appropriate personal protective equipment, the correct use of them, establishment of appropriate time table between drilling and extraction, the use of rubbing non-petroleum products are recommended in order to exposure control to lead. Occupational hygiene has traditionally focused on inhalation exposures to chemical and biological agents and during the last decade, dermal exposure assessment has received more attention. Different approaches are used to estimate dermal exposure that in this research DREAM model was used. Results show that DREAM model is flexible and can be used for dermal exposure characterization for all kinds of scenario and because of its hierarchical structure; it takes on average 15–30 min only to assess exposure for one person carrying out one task. According to the present study the DREAM is a simple and inexpensive model which is well suited to investigate exposure to lead in the mine. This model supplies an estimate for exposure levels on the skin and outside clothing layer, and gives insight in the distribution of dermal exposure over the body of exposued workers to pollutants. In addition to the advantages, the model also has some limitations, for example since few studies have been done on skin exposures, the values are presented hypothetically. In order to expand this study and provide more definitive views on the DREAM model, it is recommended that in addition to measuring the concentration of lead in air and blood samples in different working conditions, researchers use skin sampling techniques and compare the results with this model.In this study researchers suggested that skin and clothing sampling methods be used to increase the accuracy of determining the amount of lead exposure to skin. Also, the identification and risk assessment of lead exposure in workplace is recommended to determine maximum and minimum of risk level

    Keywords: Lead, Air monitoring, Biological monitoring, DREAM model
  • Vida Zaroushani*, Ali Safari Variani, Saeid Ahmadi Pages 46-58
    Background and aim

    Microwave radiations are one of the most environmental workplace factors that exposed too many workers. In microwave spectrum, radar frequency with 1-300 GHz range have varied applications such as satellite, communications, military, Network, navigation, air-traffic Control, navigation, marine and weather. Uncontrolled occupational exposure to radar radiation caused to various disease and disorders such as oxidative stress, different kinds of cancers and other thermal and non-thermal adverse health effects. Regard to the importance of identification work related carcinogenic factors in prevention and decreasing cancer related costs and lack of similar studies, this study was conducted to systematically review the research on the risk of cancer in occupational exposure to radar radiation with frequency ranges 1 to 3000 GHz.

    Methods

    The present systematic search was carried out based on PRISMA guidelines and comprehensive search strategy was focused from March 2017 to September 2018 and update on September 2018 in PubMed, ISI Web of Science, Scopus and Google scholar, MAGIRAN and SID databases with English and Persian articles without time limits were searched .Keywords were selected based on PICO principle and collected from MeSH database. comprehensive search  were accomplishment by the following search  terms  : (worker OR technician OR occupation OR military OR airline OR navy OR police officer OR  Weather )  AND (occupational exposure OR  workplace OR  long-term exposure OR  exposure  OR  radar OR  microwave OR  wireless OR  high frequency range OR  radiofrequency OR radiation OR  electromagnetic) AND (control group, cohort OR prospective OR retrospective OR follow-up OR randomized control trial OR case-control) AND (cancer OR malignant OR melanoma OR metastatic OR non-thermal effect OR biological effect OR health effect OR Adverse Effect OR risk factor OR Sarcoma OR tumor or leukemia OR neoplasm OR Carcinoma OR Hepatoma OR lymphoma OR mortality ) as single or complex terms in titles, abstracts and keywords.Then, taking into inclusion and exclusion criteria, the process of reviewing, screening and limiting the repeated and unrelated articles was carried out. In addition, manual references checking were done to retrieve the related articles. Also, any disagreements were resolved by consensus between reviewers.The inclusion criteria for selection studies were in design of case–control, cohort and randomized control trial studies, with control group and referring to the association between occupational exposure to radar radiation and all types of cancer in workers.The exclusion criteria were as follows: 1) studies without control group 2) reviews, case and field studies, 3) studies with inhumane population such as in vitro, in vivo and animal studies. 4) Studies that radar frequencies were out of considered ranges (1-300 GHz) .5) studies with other occupational or non-occupational carcinogenic risk factors (such as solvents, workplace air pollution, environmental air pollution, smoking and etc).After implementation of inclusion and exclusion criteria, data were extracted after preparation of the full text of included articles.

    Results

    A total of 533 studies was found. After removal of duplicated references, 272 studies were included for the title, keywords and abstract screening. Then, 219 studies were excluded since they did not meet inclusion criteria. Hence, 53 studies were selected for the eligibility assessment. At the end of selection process and after the quality assessment, 7 studies remained in the systematic review that including 3 case-control studies and 4 cohort studies with no randomized control trial study. A manual search of the reference lists added no more articles in this review. All included studies were from English language and external databases in various countries including USA, Germany, and France. In this systematic review, a study of clinical trials and Persian studies were not found. Finally, based on inclusion and exclusion criteria, 7 articles (4 cohorts and 3 case-control) were included, which were conducted during the 1950 to 2005 with 51898 sample size and range of ages 15–69 years that published from 1993 to 2016. Included studies examined relationship between occupational exposure to radar radiation and cancer strength among workers. Whole of the studies put determination of cancers and risk estimates in military workers. The great majority of included studies reported risk estimates with 95% confidence interval. Most included studies were conducted on testicular cancer (4 from 7 included studies) and brain cancer (4 from 7 included studies). In included studies, Relative risk were estimated, particularly about testicular, leukemia and brain cancers and mortality ratio in various types of cancers has been reported. The included studies reported no significant increase in mortality ratio about testicular cancer but increasing in relative risk were significant in two studies. There was also a significant increase in the relative risk of brain cancer in workers who occupationally exposed to radar radiation. Increase in mortality ratio due to brain cancer were significantly reported in two included studies.

    Conclusion

    The current systematic review was carried out to investigate the cancer among workers with occupational exposure to radar radiation.It is noticeable that previous related studies focused on both environmental and occupational exposure in worker and public population and it clearly did not determine the relationship between occupational radar exposure and cancer risk in workplace. Whilst, our study just focused on occupational exposure to radar radiation that lead to small number of included studies.The results of this study can be useful to prepare the occupational health policies in related to radar radiation and provide some information to conduct associated meta-analysis in future studies. On the limitations of the included studies, the continuation of experimental studies on humans with control groups, and focusing on the study of cancer-causing radar radiation in occupational exposure to workers is necessary.in this line, World Health Organization propose to conduct further differences studies  especially case-control studies.However, it should be mentioned that these results are yielded by a few numbers of available studies with no report in occupational dose and time exposure to radar frequency range. also, considering to some limitation such as few numbers of included studies, lack of data about exposure characterizations (exposure time, dose-response, average of exposure level) and demographic characterizations (average of age, average of experience, radar frequency range) it is better to continue further studies about this topic and future review studies include the congress publications without limitation in language. It is also suggested that other published articles in congresses also be used and the limitation in language of publications in the search process be removed.It is noticeable that, slight researches about occupational cancers in Iran were conducted in yet, such as studies in related to asbestosis, aromatic amines and chromium. Therefore, regarding the fast growing of cancer in developing countries like Iran, determination of occupational cancer risk factors could be useful to provide the cancer prevention and control program. So in this line, designing epidemiologic studies to focus on occupational cancers are very important especially about microwave and radar radiation.

    Keywords: Occupational Exposure, Occupational Cancer, Radar, systematic review
  • Ahmad Soltanzadeh, Hamidreza Heidari*, Shahram Arsang, Leyla Andarzkhora, Fatemeh Houshyar, Maryam Mahmudi, Hoda Rahimifard Pages 59-71

     Background and Purpose

    Anthropometric data is an essential part of the ergonomics design of the equipment, environment and work. Using anthropometric information, designers will be able to design appropriately the needs of the dimensional characteristics of the target group. According to studies, the structural characteristics of the human body are influenced by factors such as race, age, gender and type of nutrition, and vary in different nations. Several studies have shown that anthropometric data varies in different societies. Comparing the body ratios of male and female workers in some Asian countries, including Iran, shows that most aspects of the mean and all body ratios have significant differences.It is important to note that despite the high accuracy and low cost of direct measurements of anthropometric dimensions and the existence of extensive databases about them in different societies, there are still numerous problems in direct measurements of anthropometric dimensions of individuals, some of which include: the need to train individuals before measuring the dimensions that are time consuming and with their specific problems, interference in the activities of individuals and, consequently, the possibility of lack of proper collaboration in measuring the dimensions, requires the measurement of dimensions by the homosexual person, especially in Islamic countries, due to the cultural and ethical issues of those societies, and the discontent of most people, especially when it comes to repeat the measurements. Therefore, the role of the use of indirect methods, including the use of biometric regression relations, is more important for estimating the anthropometric dimensions of the target community.The advantages and limitations available for each of the commonly used anthropometric measurements on one hand, and the particular conditions of real working environments, especially in developing countries such as Iran, where physical problems and physical damage are due to poor design, on the other hand, it has led to the need for a fast, convenient, acceptable, and non-interfering procedure for workers to determine the anthropometric dimensions necessary. In this regard, attention to the biometric relationships of physical dimensions can be useful. Because in the case of finding a meaningful relationship between one or more anthropometric dimensions with other physical dimensions, it is possible to provide the anthropometric characteristics with a high degree of certainty by little time and cost and without the need for specialty.Several studies have used biometric relationships between different dimensions in the areas of forensic medicine, identification, dentistry, etc. But focusing on ergonomics and anthropometrics in designing tools and equipment in work environments has been less addressed in this area. On the other hand, researches has also been limited to small communities and cannot be generalized to the general Iranian community due to the wide diversity of ethnic and racial diversity.So, researchers have considered further studies in this area necessary. Therefore, this study aims to investigate and determine the ratio of some of the anthropometric dimensions of the indicator, which is used in various designs used by ergonomics and industrial designers, in sitting and standing static situations and in two groups of students in the age group of 18 to 26 years old.

    Methods

    In order to achieve the goals of the study, demographic data were first collected through questionnaires. The dimensions of the study included 20 positions in standing position and 18 dimensions in sitting position. Anthropometric measurements were done using caliper, tape measure, balance and checkerboard sheet (Anthropometer).To increase the assurance of measurements, multiple dimensions were selected randomly and measured by two people. The results of this study were analyzed using correlation coefficient test and if there were no significant differences between measurements by different individuals, the study continued until the end. Otherwise, training was needed for the correct examination method to be uniformed and measurements are repeated. 206 people, including 162 women and 44 men, were enrolled in this study. Sample subjects were selected randomly and clustered among male and female students. According to the main goal of the study, people with severe abnormal BMI, people with a history of musculoskeletal disorders or congenital disorders, people with severe diets, pregnant women and athletes were excluded.In order to increase the accuracy of measurements, all measurements were made in standing and sitting conditions, in a non-shoe mode and with a minimum of clothing (underwear). Also, in order to avoid interference with the measurement of some physical dimensions due to lunch, the time of measurements was selected between 8:00 and 12:00. The accuracy of the measurements was considered to be 0.1 cm in all dimensions.The results of the study were analyzed using SPSS 22 software. In this study, the distribution of anthropometric data was performed using dispersion indices and percentiles 5, 50 and 95, as well as mean and standard deviation. Also, to investigate the biometric relationships of different dimensions in relation to the height dimension of individuals in the population, multiple regression models were used. In these models, the biometric relationship of various dimensions of the body based on height dimension, which was easily measured, was examined in static sitting and standing positions.

    Results

    The results of demographic information analysis of the subjects were studied in two groups of gender and in the age range of 18 to 26 years old. Also, the 5th, 50th and 95th percentiles and standard deviations of measured dimensions in standing and sitting subjects and gender were presented, respectively. In general, 12 regression equations were obtained for standing dimensions relative to height in women and 14 regression equations for standing dimensions relative to height in men. The corresponding values ​​for sitting dimensions were 14 and 12 for men and women, respectively.In accordance with the main objective of the study which was finding relationships between the anthropometric dimensions of individuals in static states to estimate and predict other anthropometric dimensions of a person, the findings of this study showed that the mean and standard deviation of most anthropometric data in women and men have a significant difference with each other (P <0.05), and in general, its values ​​in women were smaller than males.Also, comparison of 5, 50 and 95 percentiles in standing and sitting anthropometric dimensions showed that there was a significant difference between static anthropometric dimensions in standing and sitting position in both gender groups. So that the standing dimensions in men were more than women in all three percentiles. However, in the dimensions of sitting, the amount of this difference is reduced and in some cases, such as head length, depth of chest, and abdominal depth, there is no significant difference in the 5, 50 and 95 percentiles of men and women were seen.The findings of the existing regression relations between the different static standing anthropometric dimensions and the selected index in this study, which was the height of the subjects, also showed that there is not a significant correlation between height and anthropometric dimensions of the width of the hand, the internal and external distance between the two eyes and the width of the wrist in women. In the 95% confidence interval among women, standing grip reach, length of upper limb and elbow height with correlation coefficients of 0.791, 0.742 and 0.737 have shown the highest fit with height dimension and other dimensions have shown moderate and weak correlations with dimensional dimensions. In men, the shoulder height, eye height and length of upper limb showed the highest relationship with height with correlation coefficient of 0.949, 0.867 and 0.840, respectively.Comparison of the coefficients of correlation obtained in the two gender groups also shows that in most of the dimensions measured in standing position in men, there are more correlation coefficients than women. Also, in terms of the number of dimensions, more dimensions in men than women with a height dimension have been meaningful. The relationships between different dimensions of body and height of people in this study and the appropriate and acceptable correlation coefficients obtained between the many dimensions such as eye height, shoulder height, elbow height, knuckle height, upper limb length, shoulder-grip length, standing grip and buttock knee length, with the height of the individuals, can be indicative of the fact that acceptable estimates of the dimensions can be obtained by measuring only the height of people. From the total of 38 anthropometric dimensions studied in this study (20 standing and 18 sitting positions), 26 regression relations were statistically significant (P <0.05) at 95% confidence interval for both men and women groups, separately. Although the relationships were statistically significant, they did not include the same dimensions in the two gender groups. For example, in women, sitting height and sitting shoulder height were significant and had a regression relation, but in men, no significant relationship was found between these dimensions.

    Conclusion

    Due to the limitations of anthropometric measurements during design, the use of biometric relationships can be proposed as a practical, rapid, and acceptable alternative of indirect methods. Based on the results of this study as well as other similar studies, it can be seen that stature can be considered as a suitable indicator and predictor dimension in designs that require specific body dimensions such as shoulder height, eye height, standing grip, upper limb length and elbow height.However, given that the study was conducted in a small student population, and it was not possible to select the same number of people from two groups of gender, it is suggested that, in order to increase the accuracy of the work and the reliability of the results, the complementary and targeted studies should be developed and implemented in the following the present study. So, it is expected that the anthropometric predictive tools such as a predictive software can be obtained so that, by measuring the minimum dimensions of each person as inputs, other dimensions required for design would be estimated, reasonably.Also, although examination of a large number of sitting and standing positions in this study compared to other studies has been considered as one of the strengths of the present study, it is recommended that in later studies, in addition to the relationship between dimensions measured and stature, relationships between stature and other anthropometric dimensions, which can easily be measured, is to be considered.

    Keywords: Anthropometry, static dimensions, regression, prediction, stature
  • Seyed Medi Mousavi, Rohadin Moradirad, Mohammad Hossain Beheshti, Roohalah Hajizadeh*, Fereshteh Taheri, Ismail Khodaparast, Saeid Yazdanirad, Yoosef Faghihnia Torshiz Pages 72-82
    Introduction & Objective

    Noise exposure, risk exposure in a wide range of work station, especially oil and gas industry and related companies is considered. This study was carried out to evaluate the noise before and after corrective action in 11 operational units of tanks and transportation in Abadan oil refining company.

    Methods

    First, the basic information including the location of noise sources and operating conditions of the equipment was collected. noise measurements was performed based on ISO 9612 standard before and after implementation of corrective actions, including repair or replacement of defective and worn out Parts or lubrication of moving parts  and using SLM CEL 490 mode calibrated with CEL-110/1  of casella  company was performed.

    Results

    According to the results, the NTA has the highest amount of noise (97 dB) and spherical tanks with the lowest noise (82 dB). In this study, measured total 523 stations, 115 stations with noise levels over 85 dB, 373 stations between 65 and 85 dB sound pressure level and sound pressure level less than 65 dB in 30 stations. After carrying out corrective measures to reduce noise measurements, result showed that reduction of average sound pressure level of unit 1 of oil pumping with the 2/39 dB, 1.7 dB with a unit of Control Center, pus oil pumping unit with 0.98 dB and NTA unit with 0.08 dB, carried out respectively.

    Conclusion

    Noise measurements showed that the NTA unit was one of the severest conditions from the viewpoint of noise pollution among the other units. This study confirms the need to identify the main sources of sound and prioritize different parts of the industrial unit in order to implement control schemes engineering.

    Keywords: noise, noise control, noise measurement, oil companies
  • Morteza Aghahasani, Abedin Saghafipour, Maasoumeh Farshid Moghadam, Maryam Khakbazan, Samaneh Abolkheirian Pages 83-95
    Background and Aim

    Promoting health and responding to the health needs of people and communities is the most important mission of any country's health system.In recent years،the concept of health and its determinants and on the other hand the health needs and demographic structure of societies have undergone many changes. Fair access to High quality health care seems impossible without formulating appropriate strategies and planning and utilizing human resources management principles. In other words, establishing a balance between workforce and the workload of health workers working in different areas, including suburban areas that have different demographic structure and needs compared to the urban population, is one of the health management requirements. To date, numerous studies have been done in Iran and other countries, but it can be said that the studies are mainly focused on specific areas such as treatment and have included one of the urban or rural contexts of research. Considering the variety of forms of health care systems in different countries as well as the type and variety of services and methods of study, the above studies have had a different approach than the present study. Also، timing of service delivery as the most important factor in improving productivity and optimizing the use of all available health resources and facilities، is necessary for rational and realistic human resource estimation as well as standard time setting. This study was designed to compare the timing of primary health care and the workload of staff working in Qom city comprehensive health bases in urban and marginal areas.

    Methods

    This cross-sectional study was conducted in the second half of the year 1396 (Solar -Hijri) through random sampling from two bases located in two marginal bases of the city and two urban texture bases of Qom. Over a 3-month period, 1000 people-care at comprehensive health bases and age groups for infants, children, adolescents, youth, middle aged, elderly, mothers (prenatal, pregnancy and postnatal cares) were timed. The number of bases and sample size required for the study were determined by Systematic Random Sampling and according to the population of each geographical area in Qom. The four sites studied in this study were selected from four different urban areas. The present study was conducted in 4 stages. In the first phase, in order to coordinate the supervisors and health care providers, an 18 hour workshop was held for uniformizing the method of work, the variety of services, the type of care and the content of the training provided to the target group. During this period, 10 health educators were trained. In the second phase, out of 10 trained caregivers, 4 caregivers with the highest agreement rate in terms of service time, work experience, degree and field of study were selected. Each caregiver was referred to one of the health bases studied each day. In the third step, the timing was done by the Stop Watch method. In this process, the timing of services was recorded by a stopwatch in a complete care consisting of new or periodic care and from verbal communication with the caregiver to the end of full care. Also timing of each service and its components was measured by another stopwatch. Other references to follow-up or examination of tests or referral for purely special care were not subject to timing. In addition, in the event of a power failure or the Internet, the timing process was stopped and the time was recorded, and the duration of the power outage or the Internet was calculated separately and the necessary explanations were noted at the end of the checklist. In the fourth step, after recording the service times and their components in the standard timing checklists, data analysis was performed in SPSS software version 22 using descriptive and analytical statistics including mean and standard deviation and independent t-test.

    Results

     In this study, 96.1% of clients were Iranian and 3.9% were non-Iranian. Also, 497 people (49.7%) of all target groups were living in the marginal areas of the city and 503 people (50.3% of the samples) were living in urban areas of Qom. Out of 92 referrals for healthy reproductive care, 46 subjects were timed in the marginal areas and the same number in the urban context. The mean age of the subjects was 28.5 and 31.5 years in urban and suburban areas, respectively. Also out of 88 referrals that were timed for pregnancy care (including 44 subjects in urban tissue and 44 subjects in marginal areas) the mean age of mothers in urban and suburban contexts was 28.8±5 and 27±6 years, respectively. The mean age of women was 28.8±5 and 27±6 years for prenatal care so 25±5 and 28.6±5 years for postpartum care (respectively at the comprehensive health base in urban and marginal areas). in the case of neonatal and child care the mean age was considered in terms of day (for neonatal care) and month(for child care)  and it was 18±11 as well 20±11 days(for neonatal care) and 19±15 as well17±16  month (for child care)  in urban and suburban areas. The mean age (in terms of year) for adolescent and youth care in this study was 11±4 as well 11±5 (for adolescent care) and 25±3 as well 23.5±4 (for youth care) in urban and marginal texture, respectively. Based on the findings of this study, the mean age of female middle-aged women cares in urban and suburban areas was 42± 8 years. Similarly, the mean age for middle-aged men in both areas was 40±7years. Finally, the mean age for the elderly cares was 64±4 in urban context and 66±6 in marginal context. In all service packages, except for prenatal care, there was no significant difference between the mean age of the subjects in urban and marginal areas (p <0.05). In this study, the mean of total time for prenatal and postpartum care was 23 ± 6 and 20±5 minutes. The mean time of postpartum care was 21.5 ±4.5 and 18 ±3 minutes (in marginal and urban context, respectively) and the difference was not statistically significant (p = 0.08). But, unlike postnatal care, the timing of prenatal care showed a significant difference in the marginal (27.4 ± 4min) and urban (18 ± 3min) tissue (p = 0.001). Also, pregnancy care with a total mean of 35 ± 9.5 minutes was the most time consuming care and there was a significant difference in the mean time allocated to this care in the urban (28±7min) and suburb (39±8min) context(p =0.005). Mean timing of healthy reproductive care was 7.7±3 and 6.8±2.7 minutes in marginal and urban areas respectively (the total time devoted to these cares was 7.4 ± 2.8 minutes. According to statistical tests, the difference between the time of healthy reproductive care in the marginal and urban context was not significant (p = 0.139).While the results obtained from the timing of other cares provided in the Health Reform Plan package, the average overall time for infant and children cares were 24.7 ± 5 and 22 ± 6, respectively, The mean time of neonatal care was 27±7 and 22± 4 minutes (respectively at the comprehensive health base in marginal and urban areas) and the observed difference was statistically significant (p =0.004). Also, there was a significant difference between the timing of child care in the urban and marginal areas (19± 3.5 and 25± 6 minutes respectively).In the case of middle-age women care the average overall time was 26.5 ± 4.5 min and the difference observed in timing of care (33±6 and 23±5 in marginal and urban areas) was significant (p =0.001).In contrast, the results of the study showed no significant difference between the timing of middle-aged men care in urban (26±6 min) and suburban (34±8 min) area (p =0.29) and the total time of care in this case was 31±9 minutes. The total time of the elderly care was 33± 9 min (37±8 and 27±8 in marginal and urban areas), which showed significant difference between urban basin health and urban areas (p =0.001).In addition, the mean of total time for adolescent and youth cares were, 32.5 ± 5.8 and 24 ± 6.4 min which did not show any significant difference between urban basin health and suburban areas (p = 0. 1). The mean of time taken to care for adolescents and youths was 40±6 and26±6 min in suburban texture 38±8 as well 23±7 min in urban area.

    Conclusion

    Differences in the timing of health services and work load in suburban and urban texture health contexts can be used in planning the number of appropriate manpower by the type of care, service location, and needs of the target group in order to provide high quality care in accordance with the principles of human resources. In other words, fairer access to primary health care requires more attention from planners and policymakers to demographic differences and the needs of urban and marginal regions. Further studies are recommended to compare the timing of services in different age and sex groups. A comparative study with other developing and developed countries can also highlight the strengths and weaknesses of the program.

    Keywords: Work load, Time management, Primary health care, Health care reform plan