Millions Die From Car Emission In India And China
19 December, 2012
Surge in car use in south and east Asia killed 2.1m people prematurely in 2010, says a study published by Lancet.
John Vidal reported :
An explosion of car use has made fast-growing Asian cities the epicenter of global air pollution and become, along with obesity, the world's fastest growing cause of death according to a the study of global diseases.
In 2010, more than 2.1m people in Asia died prematurely from air pollution, mostly from the minute particles of diesel soot and gasses emitted from cars and lorries. Other causes of air pollution include construction and industry. Of these deaths, says the study published in The Lancet, 1.2 million were in east Asia and China, and 712,000 in south Asia, including India.
Worldwide, a record 3.2m people a year died from air pollution in 2010, compared with 800,000 in 2000. It now ranks for the first time in the world's top 10 list of killer diseases, says the Global Burden of Disease (GBD) study.
The unexpected figure has shocked scientists and public health groups. David Pettit, director of the southern California air program with the Natural Resources Defence Council (NRDC), said: "That's a terribly high number – and much more people than previously thought. Earlier studies were limited to data that was available at the time on coarse particles in urban areas only."
According to the report, by a consortium of universities working in conjunction with the UN, 65% of all air pollution deaths are now in Asia, which lost 52m years of healthy life from fine particle air pollution in 2010. Air pollution also contributes to higher rates of cognitive decline, strokes and heart attacks.
If the figures for outdoor air pollution are combined with those of indoor air pollution, caused largely by people cooking indoors with wood, dirty air would now rank as the second highest killer in the world, behind only blood pressure.
Household air pollution from burning solid fuels such as coal or wood for cooking fell noticeably, but not having clean cooking and heating fuels remains the leading risk in south Asia.
Fine particle air pollution in India is far above the legal limits of 100 microgram per cubic meter. This can rise to nearly 1,000 micrograms during festivals like Diwali.
Improvements in car and fuel technology have been made since 2000 but these are nullified by the sheer increase in car numbers. Nearly 18m are expected to be sold this year alone. In Delhi, there are now around 200 cars per 1,000 people compared with 70-100 per 1,000 population in Hong Kong and Singapore.
Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change and director-general of the Energy and Resources Institute in New Delhi, this week suggested the need to "demand restraint measures" in Delhi, to put a check on the growing number of cars so that there was a check on pollution.
The study report “A comparative risk assessment of burden of disease and injury attributable to 67 risk factors and risk factor clusters in 21 regions, 1990—2010: a systematic analysis for the Global Burden of Disease Study 2010”  said:
In 2010, the three leading risk factors for global disease burden were high blood pressure, tobacco smoking including second-hand smoke, and alcohol use. In 1990, the leading risks were childhood underweight, household air pollution from solid fuels and tobacco smoking including second-hand smoke.
The leading risk factor in most of Asia, North Africa and Middle East, and central Europe was high blood pressure.
Worldwide, the contribution of different risk factors to disease burden has changed substantially, with a shift away from risks for communicable diseases in children towards those for non-communicable diseases in adults. These changes are related to the ageing population, decreased mortality among children younger than 5 years, changes in cause-of-death composition, and changes in risk factor exposures. New evidence has led to changes in the magnitude of key risks including unimproved water and sanitation, vitamin A and zinc deficiencies, and ambient particulate matter pollution.
In much of sub-Saharan Africa, the leading risks are still those associated with poverty and those that affect children.
However, the combined effects of physiological risk factors are probably large, with high blood pressure the leading single risk factor globally, accounting for 9•4 million deaths in 2010, followed by high body-mass index, high fasting plasma glucose (3•4 million deaths), high total cholesterol (2•0 million deaths, and low bone mineral density (0•2 million deaths).
Household air pollution from solid fuels accounted for 3•5 million deaths in 2010 and ambient particulate matter pollution accounted for 3•1 million deaths.
Child and maternal undernutrition was responsible for the next largest attributable burden of the risk factor clusters (1•4 million deaths); with childhood underweight the largest individual contributor (0•9 million), followed by iron deficiency (0•1 million), and suboptimal breastfeeding (0•5 million). Vitamin A and zinc deficiencies amongst children accounted for less than 0•8% of the disease burden.
The burdens of disease attributable to tobacco smoking including second-hand smoke (6•3 million deaths) as well as alcohol and drug use (5•0 million deaths) were substantial in 2010.
These burdens are mainly driven by active smoking, which accounts for 87% of the combined burden with second-hand smoke, and alcohol use which accounted for 4•9 million deaths in 2010.
Of the remaining risk factor clusters, occupational risk factors accounted for 0•9 million deaths in 2010, followed by sexual abuse and violence (0•2 million deaths), unimproved water and sanitation, (0•3 million deaths), and other environmental risks (0•7 million deaths).
With the exception of household air pollution, which is a significant contributor to childhood lower respiratory tract infections, the five leading risk factors in 2010 (high blood pressure, tobacco smoking including second-hand smoke, alcohol use, household air pollution, and diets low in fruits) are mainly causes of adult chronic disease, especially cardiovascular diseases and cancers.
Important differences between men and women exist for disease burden attributable to other risk factors, most notably, for tobacco smoking including second-hand smoke and alcohol use. These risks cause substantially lower burden in women than in men, because women drink less and in less harmful ways than do men, and fewer smoke or have smoked for a shorter time than have men in most regions.
In 2010, tobacco smoking including second-hand smoke accounted for 8•4% of worldwide disease burden among men (the leading risk factor) compared with 3•7% among women (fourth highest risk factor). For alcohol use, these sex differences were similarly substantial: 7•4% (third) versus 3•0% (eighth).
The effect of occupational risk factors on population health also differed between sexes—for example, the fraction of disease burden attributable to occupational risk factors for injuries was 18•5 times higher for men than for women in 2010.
Dietary risk factors had broadly similar effects for men and women with the exception of diet low in fruits, for which the fraction of disease burden attributable was 1•5 times larger for men than for women in 2010. This effect is caused by lower fruit consumption and a larger disease burden from cardiovascular disease in men.
For people aged 15—49 years, the leading risk factor worldwide was alcohol use, followed by tobacco smoking including second-hand smoke, high blood pressure, high body-mass index, diet low in fruits, drug use, and occupational risk factors for injuries.
High blood pressure, tobacco smoking including second-hand smoke, alcohol use, and diet low in fruits were all in the top five risk factors for adults aged 50—69 years and adults older than 70 years, in both 1990, and 2010, accounting for a large proportion of disease burden in both age groups.
Globally, high blood pressure accounted for more than 20% of all health loss in adults aged 70 years and older in 2010, and around 15% in those aged 50—69 years.
In south Asia, the rise of risk factors for non-communicable diseases is shown by the substantial increase in the burden attributable to tobacco smoking including second-hand smoke, high blood pressure and other metabolic risk factors, dietary risk factors, and alcohol use.
However, household air pollution from solid fuels was, despite decreases, the leading risk factor in 2010. Childhood underweight was still the fourth leading risk factor in 2010, despite its share of disease burden having more than halved in 2010. Other risk factors for communicable disease, such as suboptimal breastfeeding and micronutrient deficiencies, fell substantially in the region as child mortality decreased.
In southeast, east, and central Asia, the epidemiological transition was already well advanced in 1990, and by 2010, high blood pressure (which is commonly associated with diets high in sodium as a prominent underlying cause, tobacco smoking including second-hand smoke, and diets low in fruits were all among the five leading risk factors in these regions.
The disease burden attributable to childhood underweight and suboptimal breastfeeding had been largely eliminated in east Asia by 2010, although they remain important in southeast Asia. In these three regions, despite decreases, household air pollution from solid fuels was still a leading risk factor in 2010, ranked third in southeast Asia, sixth in east Asia, and 12th in central Asia. Ambient particulate matter pollution accounted for a larger disease burden than did household air pollution in central and east Asia in 2010, although household solid fuels is an important source of ambient particulate matter pollution in these regions.
One of the most notable findings was the effect of alcohol use in Eastern Europe, where it accounts for almost a quarter of total disease burden.
The proportion of overall disease burden attributable to childhood underweight—the leading risk factor worldwide in 1990—had more than halved by 2010, making childhood underweight the eighth risk worldwide, behind six behavioral and physiological risks, and household air pollution from solid fuels.
Child and maternal undernutrition risks collectively still account for almost 7% of disease burden in 2010, with unimproved water and sanitation accounting for almost 1%.
The magnitude of disease burden from particulate matter is substantially higher than estimated in previous comparative risk assessment analyses.
A large share of ambient particulate matter in Asia and sub-Saharan Africa originates from solid fuel. Therefore the two exposures are related, and alternative cooking and heating fuels would have benefits for people who currently use solid fuels as well as those who do not, but live in the same community.
The global burden of disease attributable to tobacco smoking including second-hand smoke has changed little, with decreases in high-income regions offset by increases in regions such as southeast Asia and, to a lesser extent, east and south Asia.
The burden attributable to alcohol use has increased substantially in eastern Europe since 1990, mainly because of a rise in the effects of heavy drinking.
High blood pressure, high body-mass index, and high fasting plasma glucose are leading risk factors for disease worldwide, with blood pressure having large effects on population health in all regions, including low-income regions in sub-Saharan Africa and south Asia.
The disease burden in south Asia and sub-Saharan Africa, caused by increased blood pressure, has increased its absolute and relative importance in risk factor rankings.
The large attributable burden for dietary risk factors such as diets low in fruits, vegetables, whole grains, nuts and seeds, and seafood omega-3 fatty acids might surprise some readers.
The traditional health education message focused on lowering saturated fat alone needs to be expanded greatly to encompass several other key components of diet, including increased consumption of healthy foods that are presently missing from most diets.
Public policy to improve the health of populations will be more effective if it addresses the major causes of disease burden. Even small reductions of population exposure to large risks will yield substantial health gains.
If predictions about huge increases in disease burden worldwide are to be proved wrong, then countries, with appropriate global public health leadership, must urgently implement measures to control exposure to leading hazards, particularly risks for non-communicable diseases.
 guardian.co.uk, “Pollution from car emissions killing millions in China and India”, Dec. 17, 2012, http://www.guardian.co.uk/environment/2012/dec/17/pollution-car-emissions-deaths-china-india
 The Lancet, Volume 380, Issue 9859, Pages 2224 - 2260, Dec. 15, 2012, http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(12)61766-8/fulltext
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