Thursday, February 26, 2009

Expect more exposure to pests and pollutants from warming

Environmental Health News: … As climate change alters wind and water patterns, there will be significant effects on how chemicals and pathogens are distributed in the environment. Researchers in the United Kingdom gathered data from scientific experts and published literature relating to the current use, distribution and human health effects of chemicals and pathogens associated with farming and raising livestock in Europe.

They then evaluated 1) aspects of climate change that could affect the movement of the pathogens and chemicals and 2) changes in how humans may be exposed through the environment -- air, water, food -- that would likely result from predicted changes in climate. Using mathematical models, the scientists predicted the effects of climate change on many aspects of indirect environmental exposures associated with agriculture that are of concern to human health. The main agents were chemicals and pathogens, including pesticides, fertilizers, industrial pollutants (metals, dioxins, PCBs, etc.), biological pathogens (bacteria, viruses), pharmaceuticals, nutrients and allergens (mold, mildew, pollen, etc.).

Climate change is likely to alter the makeup of the chemical mix in the environment and may even change chemical forms. Higher temperatures may transform contaminants into either more or less harmful varieties. Some of these may be easier for organisms to accumulate. Increases in the abundance of pests associated with agriculture are predicted, due in part to a reduced effectiveness of pesticides. This could lead to higher use of herbicides, insecticides, fungicides and medicines and the development of new types of chemicals and drugs to control the unwanted guests. The increased use of these pesticides will contribute to the growing list of human health concerns associated with pesticide exposure. Hotter and drier/wetter conditions predicted by climate change may also influence current farming practices. Droughts may require more irrigation of fields and livestock. An excess of rain will flood fields.

…Although many of these increased risks are significant and startling, the authors believe much can be done to prevent some of the impending problems and damage. Some of their recommendations include:

• Develop surveillance for the presence of pathogens in high-risk areas to greatly increase our awareness and treatment of problem areas.
• Update regulations and policies regularly in light of new scientific knowledge. Some countries are already developing policies to limit negative effects from climate change (Boston 2008). Significant time lags between new research findings and policy development will not be acceptable in a rapidly-changing environment.
• Develop models and data sets for chemical and disease pathways that have not been extensively studied. These include dust transport and flood immersion.

Sunset, from Zebulun beach in Herzliya, Israel, shot by RonAlmog, (Flickr page), Wikimedia Commons via Flickr, under Creative Commons Attribution 2.5 License

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