Exposure To Air Pollution Linked To Decrease in IQ and Short-Term Memory Among Children, Study Finds

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Steam and other emissions rise from a coal-fired power station near Lithgow, 120 km (75 miles) west of Sydney, July 7, 2011. Australia is set to slap a carbon tax of A$23 a metric ton ($24.60) on its major emitters, newspapers said on Thursday, but it has halved the number of companies liable for the tax in a bid to overcome hostility to the policy. REUTERS/Daniel Munoz

Exposure to air pollution increases the risk of decrease in IQ and short-term memory problems, a new study finds. Researchers from the Universities of Montana, Carleton, and North Carolina and the Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México have conducted a new study where they highlight the ill-effects of air pollution on the apolipoprotein E (APOE) ε4 allele that affects cognition, olfaction, and metabolic brain indices in healthy urban children and teens.

“APOE ε4 is likely playing a role in Mexico City children’s response to their cumulative air pollution exposures. Of importance for health and educational issues, since Mexico City children mostly attend underprovided public schools that do not help in the development of executive function skills and do not build cognitive reserves, the >10 point IQ difference will likely have a negative impact on academic and social issues, including bullying and teen delinquency,” said investigators Lilian Calderon-Garcidueňas, MD, PhD, The Center for Structural and Functional Neurosciences, in a press statement.

The researchers noted below-average scores in verbal and full scale IQ among children and teens living in urban areas where they are exposed to maximum air pollution. This doesn’t necessarily mean outdoor pollution.

Surprisingly, indoor pollution kills more people than outdoor pollution. Indoor pollution comes from cooking stoves and fireplaces still used by nearly 3 billion people, mostly women, in poorer countries. According to WHO estimates, indoor air pollution is responsible for 4.3 million deaths, especially in households that use wood, coal or other open-air fires, while 3.7 million die from the effects of outdoor pollution.

Others statistics revealed that 40 percent of deaths linked to outdoor air pollution were from heart disease; another 40 percent from stroke; 11 percent from chronic obstructive pulmonary disease (COPD); 6 percent from lung cancer and 3 percent from acute lower respiratory infections in children.

The statistics were quite similar for deaths linked to indoor air pollution. However, the number of deaths from COPD more than doubled due to indoor air pollution. Twelve percent of indoor air pollution deaths were among children with infections such as pneumonia.

"Cleaning up the air we breathe prevents non-communicable diseases as well as reduces disease risks among women and vulnerable groups, including children and the elderly," said Dr Flavia Bustreo, WHO assistant director-general for Family, Women and Children's Health, according to ABC News. "Poor women and children pay a heavy price from indoor air pollution since they spend more time at home breathing in smoke and soot from leaky coal and wood cook stoves."

previous study found that that even if filters are placed on doors and windows as protection from outdoor pollution, 25 percent of it can still get indoors. Research suggests outdoor air pollution exposure levels have risen significantly in some parts of the world, particularly in countries with large populations going through rapid industrialisation such as China and India. In October 2013, the National Oceanic and Atmospheric Administration released some pictures that revealed the smog problem in China was so dire that it can be seen from space.

Another study by Texas A&M University and NASA's Jet Propulsion Laboratory researchers revealed that air pollution in Asian countries is responsible for changing weathers and climate patterns. Increases in coal burning and car emissions are major sources of pollution in China and other Asian countries. Once emitted into the atmosphere, pollutant particles affect cloud formations and weather systems worldwide, the study revealed.

The condition is so bad in some Asian cities that the level of air pollution is 100 times more than the acceptable limits set by the World Health Organisation. An earlier study showed that the chances of lung cancer in such cities have increased by 400 times due to the ever-growing level of air pollution.

Latest statistics reveal that the current air pollution level in Beijing shaves off 16 years from a person's life. A study also found that estimated effects of air pollution were greater on the younger group of people than older groups.

"The potential reason is that the measurement of YLL takes into account those conditions afflicting young people or children. Giving the same weight to deaths occurring at different ages could distort policy priorities and resource allocation," Business Insider quoted environmentalists as saying.  "Most studies report that mortality risks related to air pollution are greater for older people than younger people. Our study suggests that focusing on death counts only could underestimate the burden of air pollution on young people."

The WHO's cancer research agency IARC published a report in 2014 warning that the air we breathe is laced with cancer-causing substances and should be officially classified as carcinogenic to humans.

Findings of the current study were published online in the Journal of Alzheimer’s Disease. 

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