A warming climate in the MEC region over the coming century could pose several potential direct and indirect health risks for residents of the region. The most significant direct health risk related to warming is likely to be an increase in the numbers and severity of extreme heat events, or "heat waves", which can result in physiological stress leading to illness and premature death in vulnerable individuals. Extreme weather events, especially coastal flooding, also may result in increased illness and death. Risks include direct effects of flooding as well as indirect effects on provision of water and power services. The prevalence of certain vector-borne diseases, such as West Nile encephalitis and Malaria, may increase with regional warming and increased climate variability. Another area of indirect risk involves the potential for increases in infectious diseases resulting from pathogens carried by the water supply. Finally, the formation of photochemical air pollutants, like ozone and certain particles, is enhanced at higher temperatures. Increased rates of formation of these toxic air pollutants caused by climate change would be exacerbated by increasing emissions of precursor pollutants, such as nitrogen oxides and volatile organic compounds, due to an expanding economy.
Vulnerability to these potential health risks due to climate change is likely to vary across the population of the MEC region as a function of age, socio-economic status, and pre-existing health status. Environmental stresses associated with climate change will overlay existing patterns of vulnerability in the region, which include strong gradients in asthma prevalence, social deprivation, and other factors. The impact of extreme heat events on public health in the MEC region will depend upon individual adaptability, the prevalence of publicly and privately accessible air conditioned environments, and the ability of weather services and local health agencies to warn the population of upcoming heat waves, especially the vulnerable elderly and poor. The incidence of certain vector-borne diseases may rise as spring and fall warming extend the season in which the reservoirs, vectors, and their parasites are active and as wintertime survival increases. Water-borne diseases may become more of a burden depending on how rising temperatures affect wild animal populations in the watershed area, the viability of the aquatic pathogen, and human water consumption.
In the current project, we developed a model for predicting ground level ozone concentrations for the next 100 years as a function of climate change and precursor emission scenarios, and the resulting impacts on hospitalizations for asthma and other respiratory conditions. The 12 part per billion (ppb) increase in annual average 8-hour daily maximum ozone concentration we projected in the MEC by 2030 may correspond to an additional 995 and 819 total respiratory and asthma hospitalizations, respectively. By 2100, the average daily maximum ozone in the MEC region is projected to rise by 51 ppb, which might result in around 4,150 and 3,320 additional total respiratory and asthma hospitalizations, respectively.
Summarizing the key findings of our report:
- The most significant direct health effect likely to be associated with a warming and more variable climate is an increase in summer-season heat stress morbidity and mortality, particularly among the poor elderly.
- Indirectly, climate change in the MEC region could contribute to at least three classes of adverse health outcomes: incidence of certain vector-borne diseases may rise; water-borne disease organisms may become more prevalent; and formation of photochemical air pollutants may be fostered.
- In the short term, impacts of climate change on ground-level ozone concentrations are not likely to be a major public health concern in the MEC Region. By the year 2100, the impacts become more significant, especially for asthma (6.5 percent rise in New York asthma admissions).
- It is likely that the health effects of climate change will not be distributed equally across the MEC regions inhabitants, both spatially and socio-economically.