Summary
This study was conducted to explore the hazardous effects of pesticides on pesticide exposed retailers. For this purpose, blood of total 100 pesticide workers of different age groups were sampled in different areas of district Khanewal Punjab, Pakistan. Comparison was made with 100 non-exposed persons. Analysis of blood samples was done with the help of hematological analyzer and serum collected in this study was use for different biochemical tests. Hematological parameters including HGB, RBCs count, hematocrit, MCV, MCHC, monocytes, lymphocytes, neutrophils and eosinophils vary in different diseases in the exposed and unexposed workers. The percentages of occurrence of certain diseases were high in exposed group than the unexposed groups. Biochemical parameters ALT, AST, LDH, CPK, ALP, Creatinine, urea, lipid profile tests, and tests of certain minerals showed variations of values in different diseases. The comet assay is used to check the DNA damage in lymphocytes of both exposed and unexposed groups. The pesticide exposed group has significantly high values of DNA damage as compared to the unexposed group. Therefore, it is concluded that pesticide exposure causes oxidative stress and DNA damage in the workers dealing with pesticides.
Introduction
Pesticides are one of a few couple of dangerous chemical substances discharged purposely into the earth to execute the living creatures (e.g., insects (insecticides)., weeds (herbicides), rodents (rodenticides) and fungus (fungicides). Despite the fact, the pesticide term is frequently misconstrued to allude just to bug sprays, this is likewise suitable for fungicides, herbicides and different other substances which are also used for controlling attack of pests. In the advanced farming innovation pesticides are a huge segment that has been largely been received over the globe to avert or control insects, illnesses, weeds, and other plant pathogens with an end goal to decrease or kill yield misfortunes and keep up the high quality of item (Damalas, 2009; Damalas and Eleftherohorinos, 2011).
Various major/minor advantages from uses of pesticides have been illustrated, within the most articulated being financial advantages got from the assurance of crop yield, quality and the lessening of many other expensive sources, for example, fuel and work (Cooper and Dobson, 2007; Damalas, 2009). In this manner, similarly in many other different countries, an extensive pesticides range is applied on a wide scale for the insurance of the harvests in our Pakistan. All things considered, over twenty years in recent times there was almost 11.60% development occurred in entire nation in the application of pesticide, however according to results, yield wasn’t change much by increasing such pesticides application rate (Khan, 2010). Cotton crop which is an important cash crop with imperative part in the overall nation’s economy gets a lot of pesticides, which represents over 80 % of the aggregate Pakistan use of pesticides (Khan, 2009, 2011). Around 90% of the aggregate pesticides utilize set out insecticides in nature. In excess of insecticides of 108 type, the 30 kind of fungicides, 39 sorts of weedicides, almost 5 sorts of acaricides and 6 rodenticides of six type are being utilized in Pakistan.
Pesticide sell markets are present in the urban and rural areas and supply these chemical agents for a broad range of purposes. In the domestic usage, people usually buy insect sprays or powders, rat baits, and disinfectants to use in gardens and homes. Furthermore, these chemicals can be used anywhere for the same purposes. Mostly the pesticides are used by the farmers who use them in their farms (Atwood et al., 2017). A great amount of proofs on workers who work with pesticides has reported different health problems including skin problems (Anderson and Meade 2014) and respiratory problems (Neghab et al., 2015), hematological and biochemical damages, (Gaikwad et al., 2015) along with coronary artery disease and cancer. A few researches on the fitness of pesticide retailers have recommended that exposure to active pesticide components may encourage different unfavorable health effects in this working community.
Pesticide utilization has been recorded to cause many severe health impacts. Pesticide related medical issues generally showed that the exposures of pesticides are very dangerous. A small amount poisonous effect of organophosphate results in forms of different health problems “like diarrhea, malaise, loose stools, sweating, vomiting, abdominal pain, salivation and nausea”. Average amount of poisoning can cause many problems which could dyspnea, decreased strength of muscles, tremor, miosis, ‘muscles fasciculation, bradycardia, bronchospasm, motor in coordination and also includes hypotension or hypertension. Intense poisoning manifestation could result in the coma, extreme weakness of the muscles, convulsion, extreme hypersecretion, muscular paralysis, respiratory paralysis, sustained hypotension and cyanosis (Iowa State University, 1995). Other diseases like dermatitis and asthma exacerbation are also related to the exposure of pesticides (Sanborn, et al., 2002). Pesticides exposure can also cause sensory peripheral nerve defects disease, chronic neurobehavioral, disease named as motor dysfunction (Miranda, et al., 2002; Miranda, et al., 2004) deficits in verbal’s abstraction, attention and also reduction in memory (Farahat, et al., 2003), and lastly can also causes depression and anxiety (Jamal, et al., 2002). All these effects have been suggested to impair farmers’ aptitude to fulfill all established procedures of safety (Beseler and Stallone’s, 2003).
Exposure to pesticides is also associated with many other diseases including hypersensitivity, cancer, asthma, hormone disruption, and skin allergies (Van Maele-Fabry et al., 2010). Different birth defects, reduced birth weight and fetal death are also bad impacts of exposure to the pesticide number of proofs already exist (Baldi et al., 2010; Wickerham et al., 2012). Repression of acetylcholinesterase (AChE) essentially causes influence on the nervous system of exposed organisms and bringing acetylcholine step up in the cholinergic synapse. Alongside cholinergic effects, Organophosphates also causes “oxidative stress” (Soltaninejad and Abdollahi 2009; Dettbern, et al., 2006) disturbs metabolic pathways (Karami-Mohajeri and Abdollahi 2011) cause many organ dysfunctions such as hypoxia and inadequate liver and heart tissue perfusion (Kumae, et al., 2017). In the liver they cause damage metabolically, ultrastructural, biochemically, and mitochondrial, verified by variations in hepatic biomarkers for example serum aminotransferase and indirect & direct bilirubin (Hoekstra, et al., 2013; Lasram, et al., 2009).
In the course of the most recent 20 years testing confirm that organophosphorous pesticides can affect with the immune system and immunotoxic impacts exerted in research center animals through both pathways non-cholinergic and anticholinergic (Wong et al., 1992; Bernnet and Rodgers, 1994; Vial et al, 1996;). These research studies contained documentation of histopathological changes on the cellular pathology and immune tissue, altered mutation, organs and changes in lymphocyte subpopulation and functional alteration to immuno-competent cells (Voccia, et al, 1999). In some cases, these effects on immune components and functions have been linked to alteration in disease resistance in exposed organisms.
Genotoxic potential is an essential hazard factor for long term impacts, for example, reproductive toxicology and cancer-causing. The majority of pesticides have been tried in a widespread variety of mutagenicity tests covering the chromosomal modification, DNA damage and gene mutation (dearfield, et al., 1999, Bologini and Merlo, 1995). Pesticides have been viewed as potential chemical mutagens: experimental results exposed that different agrochemicals have mutagenic properties. The genotoxic potential for agrochemical fixings is mostly low, as they yield positive outcomes in few genotoxicity tests. In single test, the minimal effective dose is very high generally. As most occupational and natural exposures to pesticides are to mixtures, the genotoxic potential assessed on single compound couldn’t be extrapolated to people.
The comet assay is a fast methodology for quantitating DNA lesions in the cells of mammalian (Singh, et al., 1988). In this method electrophoresis of incorporated cells is done and lysed on agarose on a microscopic slide. The underlying mechanism is based on the organization of “DNA” in large coiled structures that can be relaxed by electrophoresis by breaks of ribbons, forming a comet tail like effect. This method is a comparatively simple, economical and speedy technique that can be done using samples obtained from in vivo or in vitro studies, the assay is suitable to use in biomonitoring of farmers which are exposed to the genotoxic disorders (Kaur et al., 2011). In the alkaline environment, the ‘comet assay detects breaks of DNA strands and labile alkaline sites’ (Singh et al., 1988). During the last 20 years, this assay has formed into a fundamental tool for use by the specialists interested in research areas ‘ranging from environmental and human biomonitoring to DNA repair’ procedures to genetic toxicology (Fairbairn, et al., 1995).
Objectives
The major objectives of the current study were:
- To investigate the relationship of DNA damage with the occupational exposure to pesticides.
- To assess the relationship of oxidative stress with the occupational exposure to pesticides.