Lead exposure in indigenous children of the Peruvian Amazon: Seeking the hidden source, venturing into participatory research

Introduction. In 2006, a Peruvian environmental agency reported the presence of elevated blood lead levels (BLLs) in indigenous communities of the Corrientes river basin. This is a territory in the Peruvian Amazon where oil activity has been associated with serious environmental effects, with impact on an ongoing social conflict. This PhD project aimed to determine the lead sources, risk factors and pathways in children of these communities and to suggest control and prevention strategies. Given the arguments attributing the lead source to the oil activity pollution, the second objective was to clarify any potential connection between the two. This project was conducted by a collaborative research partnership with the regional health authorities and the community-based organization. The third objective was to characterize the challenges, facilitating factors and the lessons learned from the research process. Methods. Two epidemiological studies were conducted. Study I (2009) was carried out in three communities and study II (2010) in six communities with different levels of exposure to oil activity. The participants were children 0–17 years old. Data collection included: determination of BLLs, hemoglobin levels and anthropometric indicators, a risk factor questionnaire, an environmental assessment and a risk map. Data analysis included univariate, bivariate and multivariate logistic regression. Data for the third objective came from field notes, documents, interviews and a process of collective reflection. Results. Study I (n= 221) found no significant difference in the geometric mean (GM) BLLs between the communities exposed and not exposed to oil activity. Older age and being a boy were found as risk factors for BLLs ≥ 10 μg/dL. In study II (n= 346), age stratified logistic regression models indicated that children 0–3 years whose mothers had BLLs ≥ 10 μg/dL, children 0–6 years who played with pieces of lead and children 7–17 years who fished 3 times or more per week or chewed pieces of lead to manufacture fishing sinkers had a significant increased risk of having BLLs ≥ 10 μg/dL. Children who lived in communities near oil battery facilities also had a significant increased risk of having BLLs ≥ 10 μg/dL. In both studies, environmental samples showed lead concentrations below reference levels. The challenges and facilitating factors identified focused on five interrelated themes: i) mutual trust, ii) multiple agendas, iii) equal participation, iv) competing research paradigms and v) complex and unexpected findings. Conclusions. Metal lead appeared to be the main source of exposure. Playing with pieces of lead and chewing pieces of lead to construct fishing sinkers appeared to be pathways of exposure for children aged 0–6 years and 7–17 years, respectively. Mothers’ BLLs > 10 μg/dL was a risk factor for BLLs > 10 μg/dL in children aged 0–3 years. Living in a community with high exposure to oil activity was a risk factor for BLLs > 10 μg/dL. The identified connection with oil activity was the proximity of communities to oil battery facilities and thus greater access to lead from cables and other industrial waste. Despite the numerous challenges, participatory research appears to be the most appropriate approach for this type of context. The study findings led us to recommend: i) a comprehensive community-based lead control and prevention plan, ii) the introduction of substitute non-harmful material(s) for fishing sinkers and iii) secure containment of the oil company’s waste deposits.