Via the South China Morning Post: Hazardous level of trace metals in Hong Kong’s air as scientists warn of health crisis. Excerpt:
The air in China contains 10 to 20 times more fine metallic particles than in the United States, according to scientists studying samples of air pollutants collected across the country, including Hong Kong.
The city's overall PM2.5 levels are lower than in most urban centres on the mainland, but it has a higher concentration of health-threatening trace metals, the scientists say.
Nearly 20 per cent of PM2.5 particle samples collected in the city carried metals such as zinc, a hazardous element that can permanently damage DNA.
While public attention is often focused on PM2.5 levels, scientists are more concerned with the particles' composition.
PM2.5 particles, the smallest measured, lodge deep inside lungs and are the most dangerous to human health.
Several teams of scientists have studied smog in China - including Hong Kong - and at least two detected heavy concentrations of trace metals. Excessive amounts of zinc and chromium are toxic and can lead to a wide range of problems, from premature ageing to cancer.
In extreme cases, high concentrations of airborne trace metals can even damage human DNA, heightening the risk of genetic conditions that can be passed on to future generations.
Scientists warn that without tighter environmental regulations, high trace metal levels could lead to a public health crisis.
Li Weijun , a professor of environmental science at Shandong University in Jinan , said: "While the general level of PM2.5 in China is five or six times higher than the US, the amount of trace metals could be 10 or even 20 times higher."