Global Diets Link Environmental Sustainability and Human Health

by Allison Hu

Due to rising incomes and urbanization, traditional diets are being replaced by diets that are higher in refined sugars, refined fats, oils, and meats. By 2050, if these dietary trends are unchecked, they can become a major contributor to an estimated 80% increase in global agricultural greenhouse gas emissions from food production and global land clearing, which can result in species extinction (Tilman et al. 2014). Additionally, these dietary shifts are greatly increasing the incidence of type II diabetes, coronary heart disease, and other chronic non-communicable diseases that lower global life expectancies. Because the global dietary transition directly links and negatively affects human and environmental health, it is one of the greatest challenges facing humanity. If alternative diets that offer substantial health benefits are widely adopted, there is potential to reduce global agricultural greenhouse gas emissions, reduce land clearing and resultant species extinctions, and even help prevent such diet-related chronic non-communicable diseases. Therefore, the implementation of dietary solutions to the tightly linked diet-environment-health trilemma, although a global challenge, is an important and valuable opportunity to improve the environment and human health. Impactful solutions will not be easily achieved and will require analyses of the quantitative linkages between diets, the environment, and human health. Tilman et al. focus their study on these solutions, along with the efforts of nutritionists, agriculturists, public health professionals, educators, policy makers, and food industries. Continue reading

Distribution of West Nile Virus, United States

by Sarah King

West Nile virus (WNV) is a relatively new disease in North America, and consequently there is very little information available about how climate change will affect its distribution. In order to gain a better understanding, Ryan J. Harrigan and his colleagues modeled the incidence of the disease under current climate conditions (2003–2011) to predict how it will spread in the future (2013). The models proved to give a significantly accurate prediction for 2012 WNV distributions. They also projected the range of WNV for 2050 and 2080, which showed that predicted warmer temperatures and decreased precipitation would expand the range of WNV beyond its current bounds. The model and its predictive capabilities may help public health and policy officials prepare for and mitigate possible future outbreaks of WNV. Continue reading

Climatic Impacts on Japanese Encephalitis, Three Gorges Dam, China

by Sarah King

Japanese encephalitis (JE) is a prevalent, mosquito-borne infectious disease found throughout the Asian Pacific Rim and Southeast Asia and most predominately in China (Bai et al. 2014). The Chinese province Chongqing has one of the highest incidence rates of JE in the country in combination with only four other provinces, make up 50% of the incidence of JE in all of China, with only 26% of the population. Consequently, Chongqing is an interesting place to study the effect of climatic change on Japanese encephalitis, which is exactly what Yuntao Bai and his colleagues did. Bai and his team set out to identify the most important climatic variables that induce the transmission and spread of the JE virus in Chongqing from 1997–2008, and what kind of geographical incidence patters arise in relation to climate change (Bai et al., 2014). Continue reading

Asian Tiger Mosquito Targets Humans and Pets

by Emil Morhardt

As a follow-on to the previous post, this paper was just published a week ago and makes it clear that all the targets of Asian Tiger Mosquitos—transmitters of dengue, La Crosse, and chikungunya viruses in the Northeastern US—are mammals, and most of them are humans, cats, and dogs. Humans were targeted more in the suburbs, and cats in the cities. This is quite different from Culex mosquitos, another major vector of human diseases, which primarily feed on birds. Ari Faraji and his coauthors found this out by trapping mosquitos in central New Jersey, then sequencing the DNA in their blood meals. Mammalian blood constituted 84% of the meals, with humans making up 52%, cats 21%, and dog 12%. The rest came from mammals also, including, opossums, squirrels, rabbits, and deer.

Central New Jersey is at the northern limit of these mosquitos at the moment, but climate Continue reading

Asian Tiger Mosquitoes Expanding in Northeastern US

by Sarah King

Mosquitoes are known for dispersing many different kinds of diseases that affect human health. Asian tiger mosquitoes (Aedes albopictus), originating in Southeast Asia, are among the most invasive and widespread species of mosquitoes in the world. This species has been the cause of the reemergence of several mosquito-borne diseases such as chikungunya and dengue, and in the United States it is largely responsible for the reemergence of West Nile Virus. Using census information, temperature data, precipitation data, CO2 emissions forecasts, and generated maps of Ae. albopictus population distributions, Rochlin and his collgues (2013) statistically modeled projections of Ae. albopictus expansion through the next seventy years (2020s, 2050s, and 2080s). Their modeling shows that the range of Ae. albopictus will grow over the next seventy years to Continue reading