Pesticide Contamination

Pesticides cover a range of compounds that include insecticides, fungicides, herbicides, rodenticides, molluscides, nematicides, plant growth regulators among others (Aktar et al., 2009). Indicators focus on the risk and environmental impact of pesticides on water quality, human health, and death of species (Padovani et al., 2004; Damalas and Eleftherohorinos, 2011). Pesticides have benefits that include improving productivity through protection from crop losses, vector control that reduces diseases, and indirect impacts like increased food security and nutrition. On the cost side, pesticides are dangerous to the targeted and nontargeted species and when used in excess amounts may kill nontargeted plants, insects, and animal species, which can affect biodiversity and other ecosystems services (Padovani et al., 2004). In addition, pesticides may contaminate agricultural foods and exposure at application may also have effects on human health (Dagupta et al., 2007; London and Bailie, 2001; Aktar et al., 2009; Damalas and Eleftherohorinos, 2011).

The first mass cases of pesticide poisoning were reported in India in 1958 where 100 people died after consuming contaminated wheat flour (Karunakaran, 1958). This raised awareness for the need to test and examine the levels of pesticide contaminations in food in the years that followed in India. In Europe, programs began examining the levels of pesticides in food products as early as 1999, when the European Union commissioned “Monitoring of Pesticide Residues in Products of Plant Origin in the European Union, Norway, and Iceland 1999 Report” (SANCO, 2001). Such reports have continued.

The data on risk of exposure to pesticide by farm workers is scanty yet high levels of exposure have been reported above the allowable limits in some studies (Dasgupta et al, 2007). For example, a study in Vietnam that took blood samples from rice farmworkers who had been exposed to insecticides (e.g., compounds containing carbamates and organophosphates) associated with health risks such as DNA damage, birth defects, hormonal changes and fetal death (Zahm et al, 1997; Dasgupta et al, 2007). Thirty-five percent of the farmers (n=190) were reported to have acute pesticide poisoning. However, it should be noted that blood tests are not always performed to assess the levels of poisoning in farmworkers. Instead subjective surveys are performed to assess symptoms and these may not provide conclusive results (Dasgupta et al., 2007). Subjective surveys and blood and health tests should be performed in tandem. Increased surveillance of pesticide poisoning and contamination in agricultural foods is also needed to understand the potential effect and how these levels are associated with some demographic and socio-economic factors (Aktar et al., 2009). In this section we cover both aspects of measurement such as the chemical tests and health center data.