Awwal 18, 1432 H/Feb 21, 2011, SPA -- Climate change is a major obstacle to a 2004 global treaty aimed at cutting exposure to 21 highly dangerous chemicals, a new U.N.-commissioned report said. The 66-page report _ obtained by The Associated Press on Monday _ says the risks of exposure could increase if more stockpiles and landfills leak due to flooding, or other extreme weather linked to rising temperatures. Chemicals stored in stockpiles or waste dumps to be incinerated or removed later could simply wash away, become more volatile, or escape in the warmer weather through gas emissions, it says. «Significant climate-induced changes are foreseen in relation to future releases of persistent organic pollutants into the environment ... subsequently leading to higher health risks both for human populations and the environment,» AP quoted Donald Cooper, the Geneva-based U.N. treaty's executive secretary as saying, in the preface. The report was being discussed Monday at a U.N. environment meeting in Nairobi, Kenya, and is due to be released later on the treaty's website. The treaty, known as the Stockholm Convention on Persistent Organic Pollutants, or POPs, is intended to protect the environment and people's health from what it calls very dangerous chemicals that accumulate in the environment, travel long distances by air and water, and work their way through the food chain. These chemicals pose a known risk to humans and the environment because they persist in people's bodies _ damaging reproductive health, leading to mental health problems, or causing cancer or impede growth. Initially the treaty focussed on 12 chemicals known as the «dirty dozen,» such as the widely banned pesticides DDT and chlordane. The use of DDT in sprays to kill malaria-spreading mosquitoes has been allowed under exception in the treaty, but the U.N. says there are good alternatives to combat malaria and hopes to phase out DDT completely by the early 2020s.