Health Risk Characterization of Chlorpyrifos Using Epidemiological Dose-Response Data and Probabilistic Techniques: A Case Study with Rice Farmers in Vietnam

• Published in: Risk analysis Vol. 33; no. 9; pp. 1596 - 1607
• Main Authors: Phung, Dung Tri, Connell, Des, Yu, Qiming, Chu, Cordia
• Format: Journal Article
• Language: English
• Published: Hoboken, NJ Blackwell Publishing Ltd 01.09.2013; Wiley
• Subjects: Agriculture; Biological and medical sciences; Case studies; Chlorpyrifos; Chlorpyrifos - analysis; Chlorpyrifos - toxicity; Data analysis; Dose-Response Relationship, Drug; Environmental Exposure; Environmental Monitoring; Environmental Pollutants - toxicity; Epidemiology; Farmers; Health; Health care; Health risk assessment; health risk characterization; Health risks; Human exposure; Humans; Medical sciences; Methods; Monte Carlo Method; Monte Carlo simulation; Occupational Exposure; Occupational medicine; Oryza sativa; Pesticides; Pesticides - analysis; Pesticides - toxicity; Population; Probabilistic methods; probabilistic risk assessment; Probability; Probability theory; Proportional Hazards Models; Public health. Hygiene-occupational medicine; Pyridones - analysis; Pyridones - toxicity; Reproducibility of Results; Rice; rice farmers; Risk; Risk Assessment - methods; Risk management; Spraying; Studies; Vietnam; Asia; Vietnam; Chlorpyrifos; Human; Insecticide; Toxicity; Spraying; Pesticides; Risk analysis; Occupational exposure; Epidemiology; Dose activity relation; Characterization; Probabilistic assessment; Risk evaluation; Risk assessment; Health hazards; rice farmers; Organophosphorus compounds; Probabilistic model; Farmer; probabilistic risk assessment; Occupational medicine; health risk characterization; Food; Rice
• ISSN: 0272-4332; 1539-6924
• DOI: 10.1111/risa.12023

Various methods for risk characterization have been developed using probabilistic approaches. Data on Vietnamese farmers are available for the comparison of outcomes for risk characterization using different probabilistic methods. This article addresses the health risk characterization of chlorpyrifos using epidemiological dose‐response data and probabilistic techniques obtained from a case study with rice farmers in Vietnam. Urine samples were collected from farmers and analyzed for trichloropyridinol (TCP), which was converted into absorbed daily dose of chlorpyrifos. Adverse health response doses due to chlorpyrifos exposure were collected from epidemiological studies to develop dose‐adverse health response relationships. The health risk of chlorpyrifos was quantified using hazard quotient (HQ), Monte Carlo simulation (MCS), and overall risk probability (ORP) methods. With baseline (prior to pesticide spraying) and lifetime exposure levels (over a lifetime of pesticide spraying events), the HQ ranged from 0.06 to 7.1. The MCS method indicated less than 0.05% of the population would be affected while the ORP method indicated that less than 1.5% of the population would be adversely affected. With postapplication exposure levels, the HQ ranged from 1 to 32.5. The risk calculated by the MCS method was that 29% of the population would be affected, and the risk calculated by ORP method was 33%. The MCS and ORP methods have advantages in risk characterization due to use of the full distribution of data exposure as well as dose response, whereas HQ methods only used the exposure data distribution. These evaluations indicated that single‐event spraying is likely to have adverse effects on Vietnamese rice farmers.