Susmita Dasgupta, Craig Meisner, David Wheeler, Nhan Thi Lam, Khuc Xuyen The World Bank and The National Institute of Occupational and Environmental Health, Vietnam Pesticide Poisoning of Farm Workers: Implications of Blood Test Results from Vietnam

Pesticide consumption (metric tons) in Vietnam Source: FAO, 2004 Pesticide consumption has more than doubled in the past decade

In 2000, a nation-wide survey by PPD found: – 2,500 kg of banned pesticides (Methamidophos, DDT and others). – 4,753 litres and 5,645 kg of illegally imported/ counterfeit pesticides. In 2000, another survey in the South found: – 96.6% of the farmers over-use pesticides – 95% of the farmers pour residual spray into canals/ ditches/ re-apply it on other plants/ over- apply it to the same crop to get rid of it. Alarming Composition/Application of Pesticides

Vietnam has limited secondary data on Health Effects of pesticides 1.Survey of Rice Farmers (pesticide applicators) in Mekong delta. 2.Clinical Exam 3.Blood Test Methodology: Questions of Interest: 1.What is the incidence of pesticide intoxication? 2.Are self-reported data good indicators of actual intoxication? 3.What are the determinants of pesticide intoxication?

Application of pesticides: survey evidence

Health Effects of Organophosphates and Carbamates cited in Medical Literature Acute: Mild headaches Flu-like symptoms Skin rashes Blurred vision Other neurological disorders Chronic: Cardiopulmonary problems Neurological and hematological symptoms Adverse dermal effects

Blood Test for the Detection of Acute and Chronic Pesticide Poisoning Cholinesterase Enzyme (AchE)Test: (poisoning from organophosphates and carbamates) Low Acute Poisoning: Reduction of numerical value of AchE in red cells and in plasma >25% High Acute Poisoning: Reduction of numerical value of AchE in red cells and in plasma >33% Chronic Poisoning: Reduction of numerical value of AchE in red cells >66%

Specific Health Effects found in the Survey 98% of the farmers in the survey reported health problems 88% of the respondents experienced multiple health effects, with the maximum number of ailments as nine

Blood (Cholinesterase Enzyme) Test Results

(Correlation between each individual symptom and blood test results were conducted. The highest correlation found was 0.17) Self-reported symptoms are not reliable indicators of actual pesticide poisoning

Determinants of Cholinesterase Enzyme Inhibition: Regression Analysis

Determinants of Cholinesterase Enzyme Inhibition: Regression Results Farmers applying more hazardous pesticides (WHO Ia & Ib) are more likely to suffer Incidence of pesticide poisoning can be significantly reduced by suitable averting behavior Pesticide poisoning in Vietnam revealed strong provincial pattern. This raises the concern that the environment in certain regions may have been contaminated from prolonged exposure to toxic pesticides

Summary and Conclusions Health effects of organophosphates and carbamates is serious in Mekong Delta, Vietnam Self-reported symptoms have very weak associations with actual poisoning Suitable averting behavior while handling pesticides should be advocated Significant provincial differences in poisoning incidence implies that pesticide contamination may be pervasive in certain areas Tests of pesticide residues in surface/ground water and soil is necessary