Dermatitis among farmers engaged in peri-urban aquatic food production in Hanoi, Vietnam

Objective To assess whether exposure to wastewater is a risk factor for dermatitis (eczema) among farmers engaged in peri-urban aquatic food production in Hanoi, Vietnam. Methods A cross-sectional study with two follow-ups was conducted from April to December 2005 in two peri-urban communes in Hanoi, one using wastewater and another using river, rain and well water for aquatic food production. In each commune, 100 households were randomly selected and adult household members engaged in farming field work were interviewed in three surveys. Farmers who reported skin problems at the time of interviews were examined and treated by a dermatologist. Data were analysed for one farmer per household. Results The overall prevalence of dermatitis from 592 interviews was 6.3%. The commune which used wastewater had a much higher overall prevalence of dermatitis (10.4%) than the commune that did not (2.1%; P-value < 0.001). Multivariable logistic regression analyses showed that occupational wastewater contact was an important risk factor for dermatitis (odds ratio [OR] 3.0; 95% confidence interval [CI] 1.1-7.7). Duration of daily wastewater contact was not significantly associated with dermatitis. Aquaculture work in the wet season carried an increased risk of dermatitis in both communes (OR 2.8; 95% CI 1.02-7.6). The use of personal protective measures during field work and washing hands and feet after work did not reduce the risk for dermatitis. However, observations showed that these practices were applied in such a way that they were unlikely to provide effective protection against wastewater contact. Conclusion Contact with wastewater is an important risk factor for dermatitis among farmers engaged in wastewater-fed peri-urban aquatic food production. Additional studies should test preventive and mitigating measures such as improved personal protection and hygiene.