Short-Term Air Pollution Exposure Increases Health Risks Even At Levels Below International Standards: Study

New research suggests that exposure to air pollution, even at levels below safety risk thresholds, appear to increase an individual’s risk of suffering a wide range of diseases and health concerns.

In a study published last month in the medical journal The BMJ, Harvard researchers linked short-term air pollution exposure to hospitalization with certain diseases for the first time.

Even small increases in air pollution were linked to a risk of hospitalization and increased health care costs from diseases, such as the serious bloodstream infection septicemia, renal failure, and urinary tract infections, according to the findings.

Researchers analyzed Medicare inpatient hospital claims in the United States from 2000 to 2012, covering more than 95 million inpatient hospital claims for patients over the age of 65. They linked the claims to daily particulate matter 2.5 (PM 2.5) levels across the U.S. using a computer model to predict exposure from recorded air pollution levels.

PM 2.5 is made up of ultra-fine particles of soot, dirt, and dust smaller than 2.5 micrometers or 30 times smaller than one human hair. Because of its tiny size it is easily inhaled into the lungs and can enter the bloodstream, leading to disease, including cardiovascular disease and lung disease. One study indicated particulate matter air pollution kills 30,000 Americans every year.

According to the findings of this latest study, short-term exposure to air pollution, even at low levels, is linked to more hospital admissions and more hospital care costs on a much larger scale than previously understood.

The new study showed a link between short term exposure to PM 2.5 and increased risk of hospital admissions to several prevalent, but rarely studied diseases when it comes to air pollution, including septicemia, fluid and electrolyte disorders, and renal failure.

For rarely studied diseases, each 1 µg/m3 increase in short term PM 2.5 was linked to an annual increase of 2,050 hospital admissions, more than 12,000 days in hospital, $31 million in inpatient and post-acute care costs, and more than $2.5 billion in value of statistical life.

For diseases previously associated with air pollution, each 1 µg/m3 increase in short term exposure to PM 2.5 was associated with an annual increase of 3,642 hospital admissions, nearly 21, 000 days in hospital, $69 million in inpatient and post acute care costs, and $4.1 billion in value of statistical life.

Other research has shown air pollution exposure can cause lung damage similar to that seen in long term smokers and lead to emphysema.

The data also indicated a link between the risk of hospital admission and cardiovascular and respiratory diseases, Parkinson’s disease and other degenerative diseases, diabetes, phlebitis, thrombophlebitis and thromboembolism. These are diseases prior studies have linked to increased risk after air pollution exposure. The new study reaffirmed those associations.

Even after researchers focused on days where PM 2.5 concentrations were below the World Health Organizations (WHO) air quality guideline for the 24-hour average, the association between exposure and risk of hospitalization remained high.

“This study discovered several new causes of hospital admissions associated with short term exposure to PM_2.5 and confirmed several already known associations, even at daily PM_2.5 concentrations below the current WHO guideline,” the researchers concluded. “Economic analysis suggests that even a small increase in short term exposure to PM_2.5 is associated with substantial economic effect.”