Secondary pesticide exposure evident in children living with flower workers

Flower plantation workers in Ecuador can expose the children they live with to pesticides they bring home from work, producing unseen health effects in the youngsters that become more dramatic the longer they live together. Children in Ecuador who live with flower plantation workers have lower levels of an essential nervous system enzyme than children who live with adults who do not work on flower farms, report researchers for the first time. They attribute the difference to exposure to pesticides that hitchhike home on the plantation workers’ clothing, tools and skin. During the recent study, the researchers found that the children who lived the longest with a worker were four times more likely to have lower enzyme activity than children who never lived with a plantation worker. The enzyme – acetycholenesterase (AChE) – is essential to body function and development. AChE is a marker for pesticide exposure and is an early indicator of possible health effects. This secondary exposure – where children are not directly exposed to the pesticides – was thought to be so small that seeing reduced enzyme activity in the children would not be possible. However, the findings from this study provide some of the first evidence that, in fact, it is possible to measure the differences. The results highlight the need for stronger regulations to protect workers and their families from pesticide exposures on fresh-cut flower plantations, suggest the authors of the study, which is published in the journal Environmental Research. In Ecuador, 71 percent of the 14,145 pesticide poisonings between 2001 and 2007 were linked to the classes of pesticides used in flower production. Higher exposures common in plantation workers can result in pesticide poisoning. Flower production is a major export for Ecuador; the United States gets about 23 percent of its flowers from the country. Production accounts for about 5 percent of the land use in Pedro Moncayo, the region where this study took place. Given the magnitude of production, the potential for pesticide exposures is widespread. Therefore, it is important from a public health perspective to ensure that people who live in such agricultural regions are safe. AChE helps neurons fire correctly to ensure proper functioning of just about everything in the body from muscle movement to breathing. Exposure during childhood is especially worrisome because it is thought to hinder nervous system and cognitive development both right after and long after the children have been exposed. The two main classes of pesticides used in flower production – carbamates and organophosphates – impair the enzyme’s abilities to regulate the messages sent through the neurons. Workers are exposed through inhaling or ingesting the pesticide during or after application to the flowers, and also through coming into contact with it when they touch the flowers. As part of a larger study on the potential of secondary exposures, the researchers wanted to know if children of flower plantation workers were more likely to have lower AChE levels when compared to children of non-plantation workers. They measured AChE activity levels in the blood of 277 children ages 4 to 9 and compared the differences between the exposed and unexposed children. Fifty seven percent were children of flower plantation workers – considered exposed – while the rest were considered unexposed. Parents and others who lived with the children filled out questionnaires. The researchers accounted for age, gender, pesticide use within the household and other factors that might skew the results. Compared to children of non-flower workers, children living with flower workers were more than three times more likely to be in the group of lowest AChE activity Furthermore, children living with plantation workers for at least five years compared to those children who never lived with a plantation worker were more than four times more likely to be in the group with the lowest levels of AChE. Among the children in this study, mean AChE activity was 3.14 units per millilitre of blood. On average, children of flower workers had levels almost one-tenth of a point lower than the children of non-flower workers. While this study did not measure cognition or behaviour effects, the same authors observed in a related study that lower AChE activity was associated with shortfalls in executive functioning, memory and attention among the same population of children. Several barriers prevent progress toward reducing pesticides that travel home with the workers, the authors suggest. For one, many workers do not routinely shower or wash their clothes at work. This may be a lack of worker education and poor plantation infrastructure – there are no showers on site.

Environmental Health News, 11 April 2012 ; ;