Smoking bans have been found to reduce heart attacks, but how such laws bring about other improved health outcomes is less clear. Little is known about the degree to which bans reduce second-hand smoke exposure, for example.

Scientific studies have suggested that two chemicals used in food packaging, Bisphenol A (BPA) and Bis(2-ethylhexyl) phthalate (DEHP), can disrupt human endocrine systems and cause birth defects, autism and hyperactivity. While the adverse effects of BPA have been studied, the contribution of dietary exposure to total intake has not been fully investigated.

With obesity on the rise across America, particularly among lower-income individuals, it has been suggested that part of the problem may be lack of access to healthy foods. Many low-income housing areas are inundated with fast food restaurants and often lack a regular supermarket that offers fresh fruits and vegetables. The term “food deserts” is increasingly used to characterize such areas, but it is not clear if this oversimplifies the problem of obesity for certain communities.

Childhood obesity has more than tripled in the last 30 years, and its causes appear to be a complex mix of genetic, behavioral, and environmental factors. Many assume that the consumption patterns and marketing relating to sugary drinks —  a well-known target in recent years for those campaigning to end childhood obesity — might have changed because of sustained scrutiny.

Economists studying rural Africa have found that as income-generating activities shift from agriculture to more diverse types of employment in other sectors, personal income and national economic indicators rise. Few large-scale studies, however, have tested this finding.

Japan sees more local and distant tsunami events than any other country — indeed the very term “tsunami” comes from the Japanese language. The massive quake and tsunami in March 2011 that have devastated northern parts of that country are situated in a long natural and cultural history that has prompted Japan to take ever-more elaborate preventative measures.

If ever there were a natural event worth forecasting, it would be a major earthquake. Currently, there are dozens of long-term predictive models employed around the world that attempt to do just that with varying degrees of success. One such model, named EEPAS (Every Earthquake a Precursor According to Scale), attempts to predict the magnitude, location and probability of a future major quake based on indicative measures of the minor earthquakes that precede it.