Long-term air pollution exposure is linked to higher hospital admissions for medical, mental & behavioral illnesses. Stricter regulations are needed to reduce the burden on healthcare.

Long-term exposure to air pollution is associated with an increased chance of hospitalization for medical, mental, and behavioral illnesses. To reduce the burden on secondary care,stricter environmental regulations are required.

Research on the health effects of long-term exposure to ambient air pollution has often focused on deaths rather than hospital admissions and on physical health rather than mental health.

The Scottish Longitudinal Study, which incorporates demographic data from related censuses and represents 5% of the Scottish population, provided the researchers with individual-level data in an attempt to close this knowledge gap.

In total, 2,02,237 individuals at least 17 years old were analyzed. Their health and hospitalizations for any reason, infectious, respiratory, or cardiovascular diseases, and mental illness/behavior problems were monitored using data from Public Health Scotland and connected to the concentrations of four major pollutants for every year from 2002 to 2017, inclusive.

The 4 pollutants from road traffic and industry comprised:

• Nitrogen dioxide (NO2)
• Sulphur dioxide (SO2)
• Particulate matter diameter of at least 10 μm (PM10) and
• Particulate matter diameter of 2.5 μm or less (PM2.5) per 1 km2 in each person’s residential postcode

Fluctuations in pollutant levels were observed across the study period, with higher levels recorded in 2002–04. Over the entire period 2002–17 average levels of NO2, SO2, PM10 and PM2.5 were 12, 2, just over 11, and just over 7 μg/m3, respectively.
The average annual levels for NO2, PM10 and PM2.5 were lower than the 2005 World Health Organization (WHO) guidelines, but the levels of NO2 and PM2.5 were higher than the most recent 2021 WHO guidelines.

Average cumulative exposure to air pollution was strongly associated with higher rates of hospital admissions.

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Higher cumulative exposure to NO2, PM10, and PM2.5 was associated with a higher incidence of hospital admissions for all causes, and cardiovascular, respiratory, and infectious diseases before accounting for residential areas.

When fully adjusted for cumulative exposure across time, the incidence rate for respiratory disease hospital admissions rose by just over 4% and just over 1%, respectively, for every 1 μg/m3 increase in PM2.5 and NO2 pollutants.

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SO2 was mainly associated with hospital admissions for respiratory disease while NO2 was associated with a higher number of hospital admissions for mental illness/behavioural disorders.

This is an observational study, and as such, no firm conclusions about cause and effect can be drawn.

The researchers acknowledge that although they accounted for demographics, such as age, sex, ethnicity and education level, they weren’t able to account for other potentially influential factors, such as lifestyle, weight (BMI), noise pollution or the absence of green spaces.

Exposure to ambient air pollution was assessed yearly rather than monthly or daily, so masking seasonal variations, while residential postcodes had to serve as a proxy for personal exposure to air pollution.

Nevertheless, the findings echo those of previously published research, say the researchers, who suggest: “Policies and interventions on air pollution through stricter environmental regulations, long-term planning, and the shifting towards renewable energy could eventually help ease the hospital care burden in Scotland in the long term.”

Specifically, policies aimed at making the zero-emission zones (ie small areas where only zero-emission vehicles, pedestrians and bikes are permitted) more abundant in Scotland, especially in the central belt of Scotland where busy and more polluted cities such as Glasgow and Edinburgh are located, would improve the air quality and in turn lower the hospital care burden in those cities.

Reference:

1. Long-term exposure to ambient air pollution, genetic susceptibility, and the incidence of bipolar disorder: A prospective cohort study- https:www.sciencedirect.com/science/article/abs/pii/S0165178123003463)

Source-Eurekalert