Environmental Assessment of Agricultural Pesticides Used in Cotton Fields in Golestan Province

Any chemical that enters the environment has destructive effects on it. Herbicides and pesticides are no exceptions as they are made of chemical materials. Environmental Impact Quotient (EIQ) is a method to assess the impact of pesticides on the environment, evaluate the pesticides and chemicals involved in nature and their impact on the farm worker, consumers, and beneficial living organisms. Moien Aldin et al. (2014) assessed the environmental hazards resulted by the use of insecticides recorded in Iran and reported that the environmental hazards caused by insecticides per hectare of cultivated land are higher in the provinces of Kerman, Mazandaran, and Golestan compared to those of other provinces.
Bazrgar et al. (2013) reported that the environmental stresses (such as the application of pesticides) affect three main components including farm workers, consumers, and ecological components in farming, with its most negative effect related to the application of pesticides on the ecological component. In addition, the results of this study showed that increasing the use of pesticides in the field had no relation with yield in terms of the diversity of pesticides and the quantitative amount of active ingredient. Bues et al. (2004) in the study of the environmental effects of tomato production using EIQ showed that insecticides had the highest environmental impact. Considering the increasing trend in the use of pesticides in agriculture, it is necessary to study their environmental impacts. The purpose of this study is to investigate the environmental impacts of pesticides on cotton fields in Golestan province. A total of 100 cotton fields were selected around the cities of Ali-Abad and Aghghala in Golestan province over two agricultural years of 2015-2016. These farms were selected such that to include a variety of farmers. Information on various pesticides was collected from these fields based on pest type (insect, mites, and pathogenic fungi) and herbicides type of poison, the number of poisoning times, and the concentration of effective material. EIQ has been used to assess the environmental impacts of pesticides. There are two types of environmental impact indicators. The first one is the basic environmental impact indicator that is calculated for each molecule of the effective materials of herbicides as well as their toxic effects on workers, consumers, birds, fishes, birds, bees, and beneficial arthropods. The second one, called as EIQ-field use rate (EIQ-FUR), is derived from the basic environmental index and the amount of pesticide use in the field. These coefficients were calculated for the components of effect on the spray-workers, pickers, consumers, applicators, groundwater, aquatic animals, birds, bees, beneficial organisms as well as the mentioned three components. Among these components (farm workers, ecological, and consumer's components), the ecological component showed the maximum impact (71%), with the effect on farm workers (22%) and consumer component (7%) being in the next orders. the highest EIQ-FUR is related to the pesticides with a value of 93.33 and 87% of the total, and the herbicides are in the next rank. The highest EIQ is related to the impact of the pesticides on three main components of farm workers, consumers, and ecological factors, as well as the total EIQ,  was associated with the pesticides of Profenofos and Thiodicarb. The ecological component consists of four subsets including the impact on the beneficial organisms, bees, birds, and aquatic animals; with the used toxins having the most impact on beneficial organisms with 38% of total toxic effects on the main component of ecologic. The highest impact on the main component of farm workers is related to spray-workers while the most impact on the consumer component is related to the consumer organisms. The use of pest resistant cultivars, the modification of the chemical composition of pesticides, and the elimination of hazardous toxins from the list of pesticides, the implementation of winter crop aggression, the destruction of weeds, deep plowing, winter water, and appropriate drainage are other ways to reduce the use of pesticide and reduce the environmental costs of agricultural production.