Assessment of DNA damage by comet assay and ChEs
Assessment of DNA damage by comet assay and ChEs activity has been widely used as a biomarker of genotoxicity and exposure to pesticide respectively, to measure the risk related to pesticides in the exposed population . Very few studies have explored the association between DNA damage and workers occupationally exposed to pesticides in India. The aim of the present study was to estimate the effects associated with pesticide exposure, by determining DNA damage and cholinesterase activities in women workers occupationally exposed to pesticides in tea garden.
Materials and methods
Results The demographic characteristics of study participants (exposed and non-exposed groups) are summarized in Table 1. In India, tea plucking workers are usually females, while male workers in this occupation are negligible. Therefore, only female workers were included for the current investigation and equal number of age matched exposed and non-exposed were recruited to avoid discrepancies. The exposed group included 77 women workers, between 28 and 56 years of age (mean age: 45.1 ± 7.7). The non-exposed group consisted of 66 women, between 25 and 65 year of age (mean age: 40.2 ± 11.4) with no known exposure to genotoxic agents. The mean 81 5 of exposure in term of experience of exposed workers was 24.1 ± 10.1 years (range 3–48 years). The distribution of subjects with respect to age, body mass index and tobacco chewing habits from both groups was almost similar (p > 0.05). This study also observed high illiteracy rate in exposed workers (38.96%) as compared to non-exposed (21.21%) (p < 0.05). The use of PPE was described by 20.78% of the workers while 79.22% were not using any kind of personal protective measures, like gloves, boots, goggles, covering arms, face mask, etc. Thus, there was direct exposure of pesticides through inhalation, skin, and eyes. Personal history of previous experience of occupational worker had revealed that about 68% of workers had worked in tea plantation during their pregnancy up to 6 months. All the participants included in the study were non-smoker and non-alcoholic. The tobacco chewing habits of exposed group (6.49%) and non-exposed group (4.55%) considered as tobacco chewer if they take more than one packet per day or excess of once a week. The occupational workers lacked awareness related to pesticide exposure and self hygiene possibly due to high illiteracy rate (Table 1). Table 2 shows the list of pesticides approved by central insecticide board of India for use in tea plantation in India. The tea garden workers included in this study were exposed to complex mixtures of pesticides, such as herbicides, fungicides, and insecticides. These pesticides are classified as slightly hazardous to moderately hazardous according to the toxicological classification of the World Health Organization . According to the answers by female workers to our questionnaire, the frequency of pesticides application by male workers in the tea garden was varying from twice in a week to once every 15 days. The method of applications noticed in the field was with the aid of a tractor and/or manually. However, no data were available on the quantities and frequency of these pesticides used by the sprayer and/or tea garden owners.
Discussion Occupational exposure to pesticide residues is a public health concern in developing countries. In India, the entire population of workers involved in the tea garden is residing in the same location and it is obvious that there is a potential chance for exposure to dangerous chemicals. Pesticides are used in a variety of combinations and very a few studies from India examined the presence of pesticide residues in biological matrices due to occupational pesticide exposure [22,23]. In tea garden, women workers are involved in plucking of tender leaves ideal for making tea and they get exposed to pesticide through skin contact, inhalation and contaminated food . As shown in Table 2, there are different kinds of chemical pesticides are used in the tea garden. Hence, the workers in this sector are exposed to a various formulation of pesticides. Majority of the pesticides uses in tea garden have been categorised by WHO  as moderately hazardous classification. Therefore, several studies have reported toxic effect associated with pesticide exposure in the workplace [, , ].