Experts assess health impact of climate change

By Sarah Anderson

In California, where global warming may push temperatures up by 3 to 12 degrees by the year 2100, sweltering conditions may affect people’s capacity to work outdoors, increasing the risk of heat exhaustion and heat stroke among agricultural and construction workers.

That's the grim prediction in a report from the California Climate Change Center, said Tord Kjellstrom, an environmental and occupational epidemiologist with 35 years of experience in health hazards related to transportation and climate change.

Kjellstrom was among the experts on climate change and environmental health who gathered at the Climate Change Summit, hosted Oct. 17 at UCLA by the School of Public Health. According to their analyses, we may be living in a world where rising temperatures and severe weather-related events could increase the rates of water and food-born illness, infectious diseases, illnesses caused by air pollution, and heat-related illness and death.

The primary question that panelists addressed at the conference was what can the public, the public health community, and state and local governments do to prepare for and prevent weather-related illness and mortality.

"Climate change is a reality, and the consequences for human health are being realized and will only worsen without decisive action," Linda Rosenstock, dean of the School of Public Health, told about 300 participants. By bringing together many of the top thinkers and researchers in the world on this subject, she said, a public dialogue can be launched "on the effects that climate change will have on human health and what can be done."

Jonathan Patz, associate professor of environmental studies and population health sciences at the University of Wisconsin, Madison, pointed out that higher temperatures and drier weather would lead to higher concentrations of carbon dioxide that would, in turn, increase levels of allergens. This could result in higher rates of asthma, particularly in large urban centers like Los Angeles, where pollution may rise by 75% to 85%, according to some climate change scenarios.

Forecasts also indicate that climate change will affect water distribution worldwide, making dry places drier and wet places wetter. Flooding increases the risk of water contamination, tainting fish and shellfish supplies for human consumption. And changes in precipitation patterns and in the onset of winter and spring seasons are also expected to alter the geographic distribution of plants and insects.

These effects, combined with other human activities, such as deforestation, logging and road-building, can dramatically alter the range and severity of outbreaks of existing infectious diseases such as West Nile virus and malaria, and result in the emergence of new infectious agents that threaten human health. Gina Solomon, a senior scientist at the Natural Resources Defense Council, urged the public health community to increase their tracking of human diseases, monitor harmful algal blooms that could threaten beach and shellfish safety and better identify geographic areas that are vulnerable to water quantity and quality problems.

At UCLA, the public health school is playing a leading role in developing the technology and establishing the infrastructure to monitor and prevent the spread of infectious diseases worldwide, said Nathan Wolfe, professor of epidemiology. Human activity has resulted in the emergence of new infectious diseases in Africa, said Wolfe, who discussed current efforts to monitor and prevent the spread of future outbreaks.

The state of California is also doing its part by developing strategies to reduce global warming emissions, said Mary Nichols, chair of the California Air Resources Board.

The Air Resources Board is pursuing 37 early actions for reducing greenhouse gas emissions that range from developing a low-carbon fuel standard and creating systems that track refrigerants to developing guidance and protocols to help local governments reduce emissions of greenhouse gases.

"Just as Californians know what to do in the event of an earthquake, people now need to learn what to do to prepare for global warming," Solomon said.