Heavy metal ecotoxicology of vervet monkeys (Chlorocebus pygerythrus) across field sites in South Africa

Primatologists use ecological models for understanding nonhuman primate (NHP) behavior and biology. Yet few studies have focused on the impacts of naturally occurring and anthropogenically derived toxicants in NHP habitats. For humans and NHPs, toxic levels of heavy metals frequently result in poor health outcomes including improper neurological development, immune system depression, and endocrine disruption. We analyzed the concentrations of lead (Pb), arsenic (As), and cadmium (Cd) in 48 vervet monkey (Chlorocebus pygerythrus) hair samples collected from eight South African groups living in environments with varying degrees of anthropogenic disturbance. We used two systems to categorize anthropogenic disturbance. The first was based on behavioral observations, home range overlap with human modified environments, and interviews with local people. The second system used stable isotope analysis (mean delta C-13 and delta N-15 hair values) from each group to estimate the consumption of C-4 resources and the utilization of anthropogenically disturbed habitats. Preliminary analyses revealed differences in the Pb and As hair concentrations across the field sites (p < 0.05). Comparisons between anthropogenic disturbance using observations and interviews revealed differences in As (p < 0.01). In contrast, comparisons between categories using delta C-13 hair values revealed differences in Pb (p < 0.05). The results from this study suggest that multiple approaches using both qualitative and quantitative data should be employed to estimate the relationship between anthropogenic disturbance and environmental toxicants. Since many NHP populations share their habitats with humans, efforts to improve these landscapes would likely be beneficial for NHP and human health.

Automated summary

This study analyzed the concentrations of toxicants in vervet monkey hair samples collected from different habitats in South Africa and found that anthropogenic disturbance has an impact on the concentrations of lead and arsenic. Two systems were used to categorize the degree of disturbance, based on behavioral observations, home range overlap, interviews, and stable isotope analysis. The results suggest that using both qualitative and quantitative data is essential for estimating the relationship between anthropogenic disturbance and environmental toxicants.