Mancozeb and maneb are in a class of fungicides that are widely used in agriculture world-wide. In Costa Rica, these fungicides are sprayed on banana plantations via light aircraft. Animal toxicity studies suggest that maneb and mancozeb can be toxic but there are few human studies in regards to the health effects from exposure to these fungicides. The main metabolite of these fungicides is ethylenethiourea (ETU), which has also been shown to be carcinogenic in animals but not completely determined in humans.
We investigated the relationship between child time activity patterns and levels of ETU in children that live on banana plantations sprayed with mancozeb and maneb in Costa Rica.
Children in the study (n =37) were recruited from a small banana plantation village in the Caribbean coast of Costa Rica. ETU levels were measured in child urine. Urine samples (first morning void) were collected once daily for 7 days and children were also asked to complete a visual time activity diary for each of the 7 days.
All children had detectable ETU levels in the urine samples. The geometric mean for ETU for all children from the study is 5.5 μg/L ETU with a range from 1.2 – 19.7 μg/L, density adjusted. The geometric mean (GM) for ETU in the urine samples was 6.96 μg ETU/g creatinine (range= 0.96 – 25.98 μg ETU/g). The 95% confidence interval (CI) for the GM was 1.75 μg/g – 1.93 μg/g. The only categories with sufficient data were [active, outside] and [quiet, inside], since children were rarely reported being [quiet and outside] or [active and inside]. Children who were active and outside for 7 or more hours had on average 1.7 times higher levels of ETU in their first void urine the day after spraying occurred as compared to days when no spraying occurred (p<0.01). When comparing children who were active and outside 7 or more hours on days when spraying did and did not occur, there is evidence to suggest that urine ETU levels are higher on days where spraying occurred ( p = 0.007).
We report that children living in the banana plantation are highly exposed to ETU and this varies according to their activity patterns and whether aerial spraying occurred or not. Implementation of the time activity diary was a success with this group of children but the accuracy of the responses should be determined with external observations of the children.