Why does lead matter to wildlife?

Humans have known that lead is a poison since ancient times, and yet it remains one of the most pervasive public health problems to this day. When the first case of a lead poisoned loon was reported in 1987, the problem of lead poisoning in wildlife was poorly understood and little was known about what species might be affected and how.

Today, it is widely known that individual animals can be acutely lead poisoned - around 48% of adult loons collected from New England Lakes over 20 years died of lead poisoning. Around 20% of the critically endangered California Condor population are exposed to dangerously high lead levels each year and must be captured and treated to keep the population alive.

In humans, cases of fatal acute lead poisoning are rare, especially in developed countries. Nonetheless the burden of lead poisoning on society remains great. This is because of sub-lethal affects. Children exposed to even small levels of lead have lower birthweight, lower IQ and lifelong reductions in their capacity to lead healthy productive lives. The impact on each individual is small, but the cumulative impact on society is great. Recognizing this problem, we apply active surveillance to test at-risk populations, especially children, to mitigate exposure and treat affected individuals.

The impact of sub-lethal lead poisoning in wildlife is largely unknown, but exposure likely harms the health and reproductive success of exposed animals. We hope to launch a broad active surveillance approach for wildlife in the Northeastern US aiming to: 1) Quantify the extent of lead exposure in wildlife, 2) work out where different wildlife species are being exposed to lead, and 3) Estimate the impacts of lead exposure on survival and reproductive success.

Lead doesn't just affect wildlife though - many people hunt and consume wild animals as a significant part of their diet. In this context it is especially important to know if people are being exposed to high levels of lead in their diet through wildlife. For that reason we are including abundant waterfowl like ducks in our surveillance plan.