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Air pollution recognized as carcinogenic, also linked to prenatal development problems

The World Health Organization (WHO) has finally reported that air pollution causes cancer: vehicle, industrial and other forms of emissions fill the air with a toxic cocktail of chemicals and particulate matter. Meanwhile, the Guardian also reports that air pollution, combined with an environment of heavy traffic, increases the likelihood of babies being born with low birthweight, which leads to other health problems. With Hong Kong suffering from both problems, the government will need to put its foot down to improve the situation if it is serious about improving its citizens’ health.

When pollution strikes hard: Air quality in March 2010 (left), compared to better days. (WSJ)

from Kate Kelland and Stephanie Nebehay for Reuters:

Air pollution a leading cause of cancer – U.N. Agency

The air we breathe is laced with cancer-causing substances and is being officially classified as carcinogenic to humans, the World Health Organization’s cancer agency said on Thursday.

The International Agency for Research on Cancer (IARC) cited data indicating that in 2010, 223,000 deaths from lung cancer worldwide resulted from air pollution, and said there was also convincing evidence it increases the risk of bladder cancer.

Depending on the level of exposure in different parts of the world, the risk was found to be similar to that of breathing in second-hand tobacco smoke, Kurt Straif, head of the agency’s section that ranks carcinogens, told reporters in Geneva.

“Our task was to evaluate the air everyone breathes rather than focus on specific air pollutants,” deputy head Dana Loomis said in a statement. “The results from the reviewed studies point in the same direction: the risk of developing lung cancer is significantly increased in people exposed to air pollution.”

Air pollution, mostly caused by transport, power generation, industrial or agricultural emissions and residential heating and cooking, is already known to raise risks for a wide range of illnesses including respiratory and heart diseases.

Research suggests that exposure levels have risen significantly in some parts of the world, particularly countries with large populations going through rapid industrialization, such as China.

IARC reviewed thousands of studies on air pollution tracking populations over decades and other research such as those in which mice exposed to polluted air experienced increased numbers of lung tumors.

In a statement released after reviewing the literature, the Lyon-based agency said both air pollution and “particulate matter” – a major component of it – would now be classified among its Group 1 human carcinogens.

That ranks them alongside more than 100 other known cancer-causing substances in IARC’s Group 1, including asbestos, plutonium, silica dust, ultraviolet radiation and tobacco smoke.

Air pollution is highly variable over space and time.

Loomis said there was relatively high exposure in Asia, South Asia, eastern North America, some places in Central America and Mexico, as well as North Africa.

But although both the composition and levels of air pollution can vary dramatically from one location to the next, IARC said its conclusions applied to all regions of the world.

“Our conclusion is that this is a leading environmental cause of cancer deaths,” Dr. Christopher Wild, director of IARC, told the news briefing in Geneva.

IARC’s ranking monographs program, sometimes known as the “encyclopedia of carcinogens”, aims to be an authoritative source of scientific evidence on cancer-causing substances.

It has already classified many chemicals and mixtures that can be components of air pollution, including diesel engine exhaust, solvents, metals and dusts. But this is the first time that experts have classified air pollution as a cause of cancer.

Wild said he hoped the comprehensive evidence would help the WHO, which is revising its global 2005 guidelines on air quality. The U.N. agency makes on recommendations on public health issues to its 193 member states.

Asked why it had taken so long to reach the conclusion, he said that one problem was the time lag between exposure to polluted air and the onset of cancer.

“Often we’re looking at two, three or four decades once an exposure is introduced before there is sufficient impact on the burden of cancer in the population to be able to study this type of question,” he said.

17 Oct 2013

from Sarah Boseley of the Guardian:

Study links low birthweight to air pollution and traffic

For every increase of 5 micrograms per cubic metre in exposure during pregnancy, risk of low birthweight rises by 18%

Babies born to mothers who live in areas with air pollution and dense traffic are more likely to have a low birthweight and smaller head circumference, according to a large European study.

The researchers, who included a team from the UK, found that babies were smaller even in areas with relatively low levels of air pollution, well below the limits considered acceptable in European Union guidance.

For every increase of 5 micrograms per cubic metre in exposure to fine particulate matter during pregnancy, the risk of low birthweight in the baby rose by 18%.

Although they cannot establish from this research that air pollution is the cause of low birthweight, the authors of the study, published in the Lancet respiratory medicine journal, believe the link is strong enough to demand action.

“Our findings suggest that a substantial proportion of cases of low birthweight at term could be prevented in Europe if urban air pollution, particularly fine particulate matter, was reduced,” said lead author Dr Marie Pedersen from the Centre for Research in Environmental Epidemiology in Barcelona.

Low birthweight in babies is a concern, because it often predicts poorer health as children and later as adults. A small head circumference could indicate problems with neurodevelopment.

The research pooled the results of studies from 12 countries in Europe, involving more than 74,000 women who gave birth between 1994 and 2011, living in a range of different settings, from inner-city to semi rural. One of the biggest cohorts, involving 11,000 women, was from Bradford.

Dr John Wright, director of the Bradford Institute for Health Research and chief investigator of the ongoing Born in Bradford study which is following the lives of more than 13,000 families, said the findings allowed for other aspects of the women’s lives that could have led to smaller birthweight babies.

“There tends to be social patterning – poor people tend to live in inner-city areas where there is more road traffic and poorer diet,” he said. But the study had achieved “very rich data collection” on the lives of the mothers, and was able to allow for other issues that could affect the baby’s development, such as smoking. Mothers who smoked had a higher likelihood of a low birthweight baby than those who did not, but only a minority smoke, whereas everybody is affected by air pollution in the area where they live.

Wright said the study made the case for regulatory intervention. “You can stop smoking and drink less alcohol and get more physical exercise. Pregnant women do this really well. But for air pollution there is nothing much you can do. This is a classic example of public health policymaking that needs to happen.”

In a commentary with the paper, Professor Jonathan Grigg, from Queen Mary, University of London, said: “Overall, maternal exposure to traffic-derived particulate matter probably increases vulnerability of their offspring to a wide range of respiratory disorders in both infancy and later life.”

Difficult decisions needed to be made, he said. “The introduction of the low emission zone in London, UK, has had little effect on concentration of particulate matter, although the vehicle mix has been altered. UK policymakers have shied away from radical solutions to the issue, such as changing diesel-powered black cabs (which contribute 20% of London’s locally generated particulate matter) to cleaner petrol-powered alternatives.”

15 Oct 2013

Hong Kong, endemic to heavy traffic and emissions (Ecopoint Asia)

from the Associated Press in London:

Air pollution leading cause of cancer, World Health Organisation warns

Breathing ruled more dangerous than passive smoking, with risk highest in places like China

The World Health Organisation has classified outdoor air pollution as a leading cause of cancer.

“The air we breathe has become polluted with a mixture of cancer-causing substances. We consider this to be the most important environmental carcinogen, more so than passive smoking,” said Kurt Straif, head of the WHO’s International Agency for Research on Cancer.The agency evaluates cancer-causing substances.

Previously, air pollution had been found to boost the chances of heart and respiratory diseases and the agency had deemed some of the components in air pollution, such as diesel fumes, to be carcinogens.

But this is the first time it has classified air pollution in its entirety as causing cancer.

Straif said the risk to the individual was low, but the main sources of pollution were widespread, including transport, power plants and industrial and agricultural emissions. Research suggests that in recent years, exposure levels have risen significantly in some parts of the world, particularly countries with large populations going through rapid industrialisation such as China.

The most recent data, from 2010, showed that 223,000 lung cancer deaths worldwide were the result of air pollution.

A recent study commissioned by Greenpeace found air quality is taking a heavy toll in Hong Kong. It linked 3,600 deaths and 4,000 cases of child asthma in 2011 alone to pollution from 96 coal-fired power plants in Guangdong and Hong Kong.

A tourist from mainland poses for photo in front of a large outdoor banner with an image of the Hong Kong island skyline at the waterfront in Tsim Sha Tsui. (Sam Tsang/SCMP)

The expert panel’s classification was made after scientists analysed more than 1,000 studies worldwide and concluded there was enough evidence that exposure to outdoor air pollution causes lung cancer.

Straif said some of the most polluted metropolises were in China and India, where people frequently don masks on streets to protect themselves.

“I assume the masks could result in a reduction of particulate matter, so they could be helpful to reduce personal exposure,” Straif said. But collective action by governments was necessary to improve air quality.

“People can certainly contribute by doing things like not driving a big diesel car, but this needs much wider policies by national and international authorities,” Straif said.

Other experts emphasised the cancer risk from pollution for the average person was very low, but virtually unavoidable. “You can choose not to drink or not to smoke, but you can’t control whether or not you’re exposed to air pollution,” Harvard University biostatics professor Francesca Dominici said. “You can’t just decide not to breathe.”
17 Oct 2013
from Emily Tsang of the SCMP:

More lawsuits expected after WHO links air pollution and cancer

Lawyers expect employees with work-related cancer to use WHO declaration of health hazard to build case on effects of being outdoors

More workers are likely to sue their employers for work-related cancer, lawyers say, after the World Health Organisation officially classified outdoor air pollution to be cancer-causing.

Lawyers Albert Luk Wai-hung and Vitus Leung Wing-hang both said the number of claims would surge as outdoor workers suffering from cancer related to air quality had a better chance of winning lawsuits and bigger payouts.The WHO International Agency for Research on Cancer on Thursday classified outdoor air pollution as a leading cause of cancer. It is more dangerous even than second-hand tobacco smoke, according to the WHO.

Air pollution had previously been found to boost the chances of heart and respiratory diseases.

“The official declaration of the WHO will definitely raise the public awareness on air pollution and cancer,” Luk said. “I am quite sure more people will consider taking such action now there is a strong foundation to prove that working in polluted air has very serious consequences.”

Leung said it was difficult now for employees to hold their employer responsible for lung cancer related to poor air quality due to a lack of medical proof.

But the WHO declaration would be sound evidence to back the claim, Leung said.

In the long run, Leung believed the health risks of poor air quality would be made an official occupational disease, with sufferers eligible for work-injury compensation, under labour laws. Then an employee would be entitled to make claims without needing to submit the WHO findings as evidence.

The amount of compensation would be subject to assessment and would vary with age, working ability, and the severity of the health damage, Leung said.

Doctors and advocates expressed concern at the poor air quality in the city and urged the government to take more steps to safeguard public health.

Respiratory doctor Leung Chi-chiu said the lungs were frequently in contact with the air as an average person inhaled six litres of air every minute. Pollutants, especially small particles, could accumulate in the lungs.

While outdoor air pollution was a factor, he said, the major cause of lung cancer in Hong Kong remained tobacco or second-hand smoke.

Greenpeace climate campaigner Prentice Koo Wai-muk said air pollution took a heavy toll in Hong Kong and urged more action from the government.

A spokeswoman for the Environmental Protection Department said the government recognised the adverse health impact of air pollution and had a series of policies to tackle it, including phasing out highly polluting diesel commercial vehicles, reducing marine vessel emissions and tightening regional emission control with the Guangdong government.
19 Oct 2013

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