مجله دانشگاه علوم پزشکی بابل
سال چهاردهم شماره 1 (پیاپی 64، زمستان 1390)

Organophosphorus pesticides are one of the most consumable poisons in the country. Such poisons can enter water sources by different routes; since consuming some drinking water which contains an amount of poison higher than the standard level, causes undesirable effects to human health and hygiene. The purpose of the present work is to study the effectiveness of eliminating malathion from water by ultraviolet irradiation (UV) mercury lamp with a medium pressure. In this experimental study, concentrations of 0.5, 1, and 2 mg/L and pH values of 6, 7, and 9 from malathion poison were irradiated at the times of 10, 20, 30, 40, 50, and 60 minutes in a ultraviolet reactor. The amounts of malathion poison were determined by HPLC instrument and then compared before and after the irradiation. The results of the present study at different concentrations, times and pH show that the minimum reduction of malathion occurs at the time period of 10 min (%46) and the maximum reduction at the time period of 60 min (%87.25) (p<0.05). Also, the effectiveness of irradiation process decreases (from 93 to 87.25%) with increasing the poison concentration (from 0.5 to 2mg/L) (p<0.001). On the other hand, the efficiency of the process increases with pH increase. The present study shows that applying UV irradiation for 60 min. with the concentration of 0.5 mg/l and pH=9, has the most effectiveness on reducing malathion poison content of water. Therefore, the application of UV reactors could be considered as an appropriate method for the treatment of waters contaminated with these poisons.

Removal of trihalomethanes (THMs) due to carcinogenic effects in liver, bladder, kidney and central nervous system dysfunctions is very crucial. Elimination of THMs precursors from drinking water resources is the most important step for inhibition of THMs formation. The aim of this study was to investigate the adsorption of humic acid (HA) onto modified pumice with Hexadecyl Trimethyl Ammonium Bromide (HDTMA-Br). This experimental study was carried out in chemistry laboratory of water and wastewater of Hamadan University of Medical Sciences, Hamadan, Iran. Apparent characteristics and chemical structure of pumice was determined via scanning electronic microscope (SEM), X-Ray diffraction (XRD) and X-Ray fluorescent (XRF) techniques. HA concentration was determined by photometry on 254nm. Langmuir, Freundlich and Temkin models and pseudo-first and pseudo second-order kinetics were used for adsorption isotherm and kinetics studies. Elevation of preliminary concentration of HA, adsorbent dosage and contact time led to increasing of HA adsorption. Increasing of pH in the range of 3 to 12 led to decreasing of adsorption and the experimental maximum adsorption occurred in pH: 3. Adsorption of HA onto modified pumice complies with Langmuir (R2=0.99) and pseudo second-order kinetic (R2=0.99). Maximum experimental (Qexpmax) and theoretical adsorption (QCalmax) was 22.5 mg/g and 29 mg/g, respectively. Langmuir constant (b) was 0.8 L/mg. The results of this study showed that in acidic condition the modified pumice with HDTMA-Br has an appropriate efficiency on HA adsorption.

The BTX compounds consist of benzene, toluene and xylenes are volatile organic compounds and are present in fuels and industrial solvents. Its emission to air and exposure to these compounds threats human health. Thus, it is necessary to control these compounds concentration in acceptable limit. Therefore, the purpose of this research was to survey BTX removal ability of a compound of iron and copper oxide metallic nanoparticles which have catalytic properties and also Zeolite as a sorbent and media for nanoparticles. In this experimental study, samples were taken from inlet and outlet airflow of reactor for BTX and CO2 concentration determination. Zeolite filters without nanoparticle and a compound of zeolite with zero valence iron and copper oxide nanoparticles which contains 4.5% of nanoparticles and with 1-2mm of zeolite grains size as much as 200g were prepared and the BTX removal by each filter in a 30cm in length and 4.5 cm in diameter column as reactor determined. The removal efficiency of benzene in the filter without nanoparticle (78.30±5.37%) was more than Iron and copper oxide nanoparticles (49.64±4.19%). But, for the toluene (67.09±4.23%) and xylenes (39.86±2.04%, 47.59±3.24% and 80.73±5.98%, respectively for p, m and o-xylenes) in iron and copper oxide nanoparticles filter it was further than the filter without nanoparticles (toluene 62.10±3.25% and xylenes respectively 30.20±1.84%, 32.15±3.39% and 18.80±3.39%). Also, the pollutant complete decomposition was higher in the filter containing nanoparticles (82.78% versus 16.44%). Average removal efficiency of BTX in the filter without nanoparticle was 43.31% and in the filter with iron and copper oxide nanoparticles was as much as 56.98%. As the obtained results the filter of zeolite without nanoparticle mainly removes the BTX compounds by absorption or incomplete decomposition. While, the zeolite filter with iron and copper oxide nanoparticles performs decomposition of the BTX more completely to CO2.

Increasing of world population and excessively consumption of the needed materials result to greatly household solid wastes generation that can threaten human health and environment. Thus, application of appropriate methods for solid waste disposal is effective on community health. This study was performed to identify the capability of native earthworms of Mazandaran province (Iran) for compost production from household solid wastes.

In this cross sectional study, the types of earthworms were separated based on appearance characteristics. Plastic bin, loam soil, sand and animal fertilizer were used for bedding. 50gr of vegetable (lettuce) was poured on the bed. Earthworms with a certain number and weight were located on soil bed. Sequential water was added to beds for moisture control. Seventeen and thirty-five days after loading, the soil of different beds were assessed for chemical and microbiological analysis.

The organic matter, organic carbon, nitrogen, phosphorous and electrical conductivity in initial substrate and vermicompost increased from 16.8% to 40.2 and 45.2%, from 1.95% to 3.9 and 5.85%, from 1.1% to 3.6 and 3.9%, from 1.8% to 2 and 2.6% and from 344 to 372 and 1068 microsiemens per centimeter, respectively. Ash percentage, C/N ratio and total coliforms in initial substrate and vermicompost decreased from 83.2% to 65% and 59.8%, from 1.75% to 1.63% and 1.49 %and from 4.5×106 to 3.3×103 and 1.3×103 MPN/100ml, respectively.

The results of this study showed that earthworms can produce compost from household solid wastes during 17 days.

Conventional processes of drinking water disinfection could not completely remove contamination indicator bacteria. So, application of new technologies like ultrasonic process has been considered for drinking water disinfection. In this study, the performance of the ultrasonic process on removal of E. coli and E. faecalis from drinking water was evaluated. In this cross-sectional study, synthetic solution contained E. coli and E. faecalis with populations of 103, 105, 107 and 109 cfu/mL (Colony Forming Unit/ milliliter) were used. After microbial seeding, drinking water samples were exposed to ultrasonic waves with the cycle of 2, 6 and 10 Pulse/s in 5 and 10 minutes. A measurement criterion of the disinfection performance was removal efficiency of indicator bacteria. Microbial colonies were counted by McFarland and plate count methods. The ultrasonic power and microbial concentration in the process of inactivation of bacteria were compared by using McFarland method. In this study, the removal performance of E. coli with colony density of 103 cfu/mL and the sonication cycle of 2 pulse/s was 1.1 log, while in the sonication cycles of 6 and 10 pulse/s was 3 log (p<0.009). Also, the removal performance of E. faecalis with colony density of 103 cfu/mL, the sonication cycle of 2 pulse/s and retention time of 5 min was 0.52 log which had significant difference in compared to the sonication cycles of 6 and 10 pulse/s which was 3 log (p<0.001). The removal efficiency of all bacterial populations was 3 log, in retention time of 10 min. By increasing the initial population of the bacteria, the performance of the disinfection process was significantly decreased (p<0.001). The result of this study showed that the ultrasonic process was effective in removal of E. coli and E. faecalis from drinking water and its efficiency was independent from bacterial population.

Computer users are susceptible to the development of musculoskeletal symptoms, with prevalence as high as 50% and the association between musculoskeletal disorders and sitting posture in the occupational setting has been confirmed. This study was designed to develop and evaluate a stage-matched intervention (SMI) in order to prevent and decrease musculoskeletal disorders among Iranian computer users, in Qazvin, Iran. This Quasi experimental study was conducted on 150 computer users who spent at least 20 hours per week. They were randomly divided into experimental and control groups. The stage matched intervention was designed based on main constructs derived from the theory of planned behavior match to the individual’s stages of readiness for MSDs preventive behavior. A control group pre-and post-test design was used for evaluating the impact of the SMI. Educational intervention program lasted eight weeks. The intervention group, compared to the control group, showed significant improvements in stages of change for preventive behavior from 2.63±0.71 to 3.49±1.05 (p<0.001), attitude from 17.92±6.54 to 21.61±4.73 (p<0.05), perceived behavior control from 9.12±2.92 to 15.58±3.23 (p<0.001) and ergo-knowledge 8.09±2.61 to 14.07±1.89 (p<0.001). The overall incidence of musculoskeletal problems in the intervention group showed a greater trend towards reduction, falling significantly from 40.16% to 35.33% compared with the control group, which fell from 40.11% to 40%. The study showed education is effective in reducing musculoskeletal problems. Therefore, appropriate training should be given to people who work with computers continually.

The BTEX chemicals (Benzene, Toluene, Ethyl benzene, and Xylene) are volatile monoaromatic hydrocarbons. Motor vehicles and fuels are examples for major sources of these environmental pollutants emission. They have harmful health effects. To reduce their health influences, monitoring their concentrations and controlling these pollutants in ambient air is indispensable. The aim of this study was to survey 24 hour variations of BTEX concentration in the ambient air of Tehran, Iran. In this cross sectional study, round-the clock concentration variations of these compounds in the atmosphere of Tehran metropolitan city were surveyed. Two air quality monitoring stations, Aghdasieh and Ray, in two different locations in the city were applied. Twenty four hour sampling was carried out by an online sampler on a monthly basis. The mean concentration of benzene (63.24±11.19 ppb), ethyl benzene (38.23±9.08) and xylene (14.13±3.29), in Ray was higher than Aghdasieh (16.57±5.86, 5.08±1.67 and 5.96±1.89, respectively) and the mean concentration of toluene in Aghdasieh (9.11±1.16) was higher than Ray (7.6±1.78). The results showed correlations among the concentrations of pollutants in each station in most cases and between two stations (p< 0.05). According to the results, despite of the different concentrations of pollutants for two studied stations; a similar trend of daily concentration changes was seen in the stations. This similar trend can be useful in 24 h concentrations prediction of BTEX in ambient air for different places.

Noise induced hearing loss (NIHL) is one of the most common occupational diseases. The basis of hearing impairment may be a combination of mechanical and metabolic factors. Since many causes of hearing loss are preventable. The main goal of study was to assess the effect of cigarette smoke on hearing impairment and occupational noise induced hearing loss. This cross-sectional study was conducted on 439 workers of a large home appliances factory in vicinity of Tehran that exposed to noise levels exceeding 85 dB. Required data were obtained by direct interview and audiometric test (PTA-Pure Tone Audiometry). Workers were divided into two groups of smokers and non-smokers. The hearing loss was compared in two groups based on two models. In model 1, the hearing threshold differences was higher than 30 dB between 4000 and 1000 Hz; and in model 2, hearing threshold level was higher than 25 dB at 4000 Hz. The frequency of hearing loss in smoker workers was higher than non smokers. Based on model 1: Odds Ratio: 10.29, p<0.001 and CI95%: 4.86-21.8 and based on model 2: Odds Ratio: 5.07, p<0.001and CI95%: 3.19-8.07). In addition in our study hearing impairment was significantly higher in smokers than non-smokers (Odds Ratio: 4.14, CI95%:1.29-13.27, p< 0.01). It can be concluded that smoking may accelerate NIHL and hearing impairment, so establishment of educational courses of smoking cessation in workplaces may be a useful method to decrease the severity of noise induced hearing loss and hearing impairment in workers.

Increasing population growth and shortage of drinking water in arid and semi arid countries like Iran has made optimal use of water in different uses. Give attention to these limitations and water quality due to bottled water use is considered as a serious solution in distribution of sanitary water. Some of the pollutants such as nitrate and nitrite and water components may lead to undesirable effects such as carcinogenesis, cardiovascular disease and hypertension, and effect on the nervous system. So, consumers should be aware of the quality of the water. The purpose of this study was to determine the amount of nitrate and nitrite in some bottled waters in Babol city, Iran.

This cross-sectional and descriptive study was performed on 28 samples of 14 bottled water factories which selected randomly. Two samples of each factory were gathered once every two weeks. The amount of nitrate and nitrite was measured by DR/2000 spectrophotometer. Limit for nitrite in drinking water was 0.2 mg/L and for nitrate was 50 mg/L. Bottled water were classified from A to N brand and then evaluated and compared.

Maximum amount of nitrate and nitrite was 35.2 and 0.0462 mg/L, respectively and minimum amount of nitrate and nitrite was 8.36 and 0.0049 mg/L, respectively. Nitrate and nitrite of all samples in standard limits was less than 0.2 and 50 mg/L.

The results of this study showed that the amount of nitrate and nitrite in 14 different brands of bottled water available in Babol city is based on International and National standards and do not threaten the health of consumers.

Increasing of world population growth causes increasing of water consumption and wastewater production. As well as wastewater discharging to surface and underground waters results to quality decreasing of these resources. One of the most suitable methods for removing contaminants from natural water is the use of wetland structures. The aim of this study was to assess the ability of domestic wastewater treatment by Marzon Abad wetland, Babol, Iran.

In this analytical study, 12 water samples were taken from influent and effluent locations in two seasons of high and low rainfall. The samples were studied for the type and the number of bacteria, physical and chemical parameters such as temperature, turbidity, NO3-1, NH3, PO4-3, PH, EC (Electrical Conductivity), COD (Chemical Oxygen Demand) and BOD (Biochemical Oxygen).

Mean value obtained from wetland influent included BOD5=17.4±5.3, COD=27.4±7.5 and turbidity=317±284, and mean value obtained from wetland effluent included BOD5=10.4±2.3, COD=16.3±4.45 and turbidity=8.7±8. Significant difference between average influents and effluents were observed in the above mentioned parameters (p = 0.027, 0.028 and 0.028, respectively).

The results of this study showed that Marzon Abad wetland has ability to purify domestic wastewater.

Considering the existence of valuable natural resources such as forest, river, sea and agricultural areas in Mazandaran province on the one hand and development of industrial and agricultural centers on the other hand, supervision and control of environmental health condition is necessary. This study was done to evaluate Pb, Cd and Zn concentrations in the industrial, agricultural areas and highway soils of Amol and Babol towns, Iran. In this cross sectional study, 192 soil samples based on easy sampling were collected from studied areas. These samples were dried in oven and grounded and then passed through polyethylene sieve with 2mm holes. PH, Organic Carbon, Cation exchange capacity and texture of soils were determined based on ASTM (American Standards for Testing of Materials (ASTM). Extraction of samples was performed by HNO3 and HCL. Zn, Cd and Pb (mg/Kg) in soil were determined by Atomic Absorption Spectrophotometer Perkin-Elmer 603. Mean concentration of Pb in the industrial, agricultural and highway soils was 213±132, 19.7±9.5 and 84±38 mg/Kg, respectively. Mean concentration of Cd in the industrial, agricultural and highway soils was 4.9±3.8, 1.9±1.2 and 0.95±0.4 mg/Kg, respectively, and mean concentration of Zn was 214±111.5, 112±47 and 107±39.5 mg/Kg, respectively. Maximum of Pb, Cd and Zn concentrations was 345, 8.5 and 325.5 mg/Kg, respectively that in industrial areas and highway it was significantly more than agricultural areas (p< 0.05). Results of this study showed that the soil of industrial areas and highway of Amol-Babol is relatively polluted. Therefore, more supervision on removal of all pollutants is necessary.

In dental science, paying attention to prevention and health is prior to treatment. Some studies and researches demonstrated that factors like the lack of information and learning about oral hygiene, the lack of prevention, and patients neglect cause periodontal diseases and dental caries increase. This study was done to assess the effect of oral and dental hygiene education by using the book on the knowledge of caries preventive behaviors in the guidance school students. This analytical study was performed on 150 students of two girl's and boy's guidance schools of Babol town, Iran. At the first, they filled pre-test papers for assessment of their knowledge and then, they used a book about dental health and oral hygiene. After 4 weeks, they filled again the same papers as post-test. So the level of their knowledge was measured (in the form of a test) and compared. In this study, the average of scores in pre-test and post-test was 7±2.8 and 8.2±2.3, respectively. The level of knowledge between the girls (9.14± 2.72) and boys (7.22±2.96) increased (p= 0.001, p= 0.007). In the girls, the level of knowledge before and after education was more than the boys (p=0.000). But the difference of increasing of knowledge between the girls was not significant in compared to the increasing of knowledge between the boys. Also, no relation was found between the scores of pre-test and post-test and parent's educational level. The knowledge level of all students (boys and girls) increased in post-test. The results of this study showed that indirect education with book is effective in increasing their knowledge.