A new United Nations study will examine the influence of climate change and some of the world's most hazardous chemicals on human health and the environment. The 12-month study, announced by the Secretariat of the Stockholm Convention, will provide the scientific community and policy-makers with a better understanding of the effects of climate change on emissions, environmental distribution, toxicity and exposure to what is known as persistent organic pollutants (POPs). The Stockholm Convention targets hazardous pesticides and industrial chemicals that can kill people, damage the nervous and immune systems, cause cancer and reproductive disorders and interfere with normal infant and child development. Over 20 substances are already banned under the 2001 Convention, whose objective is to protect human health and the environment from POPs. According to Fatoumata Keita-Ouane, a scientist with the UN Environment Programme (UNEP) who is leading the study, some data suggest that higher temperatures can make wildlife more sensitive to exposure to certain pollutants. In the Arctic region, climate change can be expected to alter the exposure levels of marine mammals such as seals or the polar bear to toxic substances through a variety of means, including the melting of the ice caps. "Exposures to POPs in combination with other factors, such as the expanding range of disease vectors and immune suppression, could also have a detrimental effect on certain organisms, the food web and biodiversity," said Dr Keita-Ouane. Also, a rise in the levels of POPs found in air and water due to releases from melting ice and snow, combined with possibly higher emissions induced by climate change, would augment the vulnerability of exposed organisms including humans, either directly or through the food chain, resulting in greater adverse impacts on human health and the environment. The study, which will involve more than 10 organisations in five countries reviewing the latest science to inform the assessment of current and new POPs, was announced to coincide with Europe's 5th Environment and Health Ministerial Conference in Parma, Italy, which ends today.