Resources

The global obesity epidemic is getting worse, especially among children, with rates of obesity rising over the past decade and shifting to earlier ages. In the US, roughly 40% of today’s high school students were overweight by the time they started high school. Globally, the incidence of obesity has tripled since the 1970s, with fully one billion people expected to be obese by 2030. The consequences are grave, as obesity correlates closely with high blood pressure, diabetes, heart disease and other serious health problems. Despite the magnitude of the problem, there is still no consensus on the cause, although scientists do recognize many contributing factors, including genetics, stress, viruses and changes in sleeping habits. Of course, the popularity of heavily processed foods — high in sugar, salt and fat — has also played a role, especially in Western nations, where people on average consume more calories per day now than 50 years ago. Even so, recent reviews of the science conclude that much of the huge rise in obesity globally over the past four decades remains unexplained.

An emerging view among scientists is that one major overlooked component in obesity is almost certainly our environment — in particular, the pervasive presence within it of chemicals which, even at very low doses, act to disturb the normal functioning of human metabolism, upsetting the body’s ability to regulate its intake and expenditure of energy. Some of these chemicals, known as “obesogens,” directly boost the production of specific cell types and fatty tissues associated with obesity. Unfortunately, these chemicals are used in many of the most basic products of modern life including plastic packaging, clothes and furniture, cosmetics, food additives, herbicides and pesticides. Ten years ago the idea of chemically induced obesity was something of a fringe hypothesis, but not anymore.

At least 14m tonnes of plastic pieces less than 5mm wide are likely sitting at the bottom of the world’s oceans, according to an estimate based on new research.

Analysis of ocean sediments from as deep as 3km suggests there could be more than 30 times as much plastic at the bottom of the world’s ocean than there is floating at the surface.

The e-waste industry is booming in Southeast Asia, frightening residents worried for their health. Despite a ban on imports, Thailand is a center of the business.

Crouched on the ground in a dimly lit factory, the women picked through the discarded innards of the modern world: batteries, circuit boards and bundles of wires. They broke down the scrap — known as e-waste — with hammers and raw hands. Men, some with faces wrapped in rags to repel the fumes, shoveled the refuse into a clanking machine that salvages usable metal. As they toiled, smoke spewed over nearby villages and farms. Residents have no idea what is in the smoke: plastic, metal, who knows? All they know is that it stinks and they feel sick.

The factory, New Sky Metal, is part of a thriving e-waste industry across Southeast Asia, born of China’s decision to stop accepting the world’s electronic refuse, which was poisoning its land and people. Thailand in particular has become a center of the industry even as activists push back and its government wrestles to balance competing interests of public safety with the profits to be made from the lucrative trade. Last year, Thailand banned the import of foreign e-waste. Yet new factories are opening across the country, and tons of e-waste are being processed, environmental monitors and industry experts say. “E-waste has to go somewhere,” said Jim Puckett, the executive director of the Basel Action Network, which campaigns against trash dumping in poor countries, “and the Chinese are simply moving their entire operations to Southeast Asia.”