Extremely small particles of pollution have the potential to evade the lungs' protective filter system and end up deep in the body, scientists suggest.

Researchers speculate the particles could then build up in blood vessels and raise the risk of heart disease.

China's air quality inspectors found problems at more than 3,000 companies in the first three months of this year, of which a large proportion were found to be falsifying data, the environment ministry said on Friday.

Nine out of 10 people on the planet breathe polluted air, even outdoors, the World Health Organisation said.

Some 92% of the population live in places where air pollution exceeds WHO limits, which can contribute to lung cancer, heart disease, and strokes.

The south-east Asia and western Pacific regions account for nearly two out of every three such deaths, it said, with poorer countries "getting worse".

Fall in Ho Chi Minh City means a whole lot of pollution.

The future of southern Vietnam’s air quality looks black indeed.

This week, the U.S. Consulate on leafy Le Duan Street reported “unhealthy” levels of particulate pollution, mainly during peak commuting hours.

Tiny particles of pollution have been discovered inside samples of brain tissue, according to new research.

Suspected of toxicity, the particles of iron oxide could conceivably contribute to diseases like Alzheimer's - though evidence for this is lacking.

The levels of dust in many places are twice the acceptable limit

A new study from Ho Chi Minh City's environment department has found an increase in dust and toxic gas in many urban areas, warning that motorbike riders can be exposed to major health risks.