The World Health Organisation (WHO) has warned that there is a definite link between diesel engine exhaust fumes and developing cancer.
The WHO is calling on Governments to take action to control diesel emissions.
The International Agency for Research on Cancer (IARC), which is part of the WHO, has classified diesel engine exhaust as causing cancer in humans, based on sufficient evidence that exposure is linked to an increased risk for lung cancer.
The WHO says there has been mounting concern about the cancer-causing potential of diesel exhaust, particularly based on findings from studies of workers exposed to diesel emissions.
It says the scientific evidence has now been reviewed thoroughly and there is now sufficient evidence for the carcinogenicity of diesel exhaust.