Earlier this month, it was discovered that air pollution can be as harmful as smoking a pack of cigarettes every day. The link between air pollution and respiratory diseases, allergies, lung cancer, strokes and even diabetes was established long ago. However, a new study says even short-term exposure to polluted air can shorten a person’s life span.
The recent study reveals that as the levels of air pollution rise in an area, so do the number of deaths. It highlighted that even a short period of exposure to very fine pollutants could prove to be deadly. Environmentalists believe this means air quality targets set by monitoring agencies are still too lenient.
Published in The New England Journal of Medicine on August 22, the study is the largest to have been carried out across the globe measuring the short-term impact of pollution on death rates.
The study’s authors tracked the levels of particulate matter (PM), or pollutant particles, in air and daily deaths in 652 cities in 24 countries over a span of 30 years. The countries included those from East Asia, Europe, North America, Latin America and Africa.
What they found was: “short-term exposure to PM10 and PM2.5 and daily all-cause, cardiovascular, and respiratory mortality in more than 600 cities across the globe.”
PM10 is particulate matter in air measuring 10 micrometres or less, whereas PM2.5 is any matter 2.5 micrometres in diameter or less. PM 2.5 is considered to be very fine particulate matter. This study showed that even tiny pollutants—40 times narrower than a human hair—in air can increase mortality.
Worsening air quality
To measure air quality, scientists usually look at two quantities: particulate matter and ground level ozone gas. The higher the concentration of these two variables, the more polluted is the air. The World Health Organisation says that more than 90% of people around the world live in areas exceeding the established guidelines for healthy air.
Air pollution contributed to almost five million deaths globally—nearly 1 in every 10—in 2017, according to ‘The State of Global Air 2019’, a report by the Health Effects Institute and the Institute for Health Metrics and Evaluation’s Global Burden of Disease Project Boston, USA.
The report states that air pollution is the fifth leading cause of death worldwide. It reduced a person’s life expectancy by one year and eight months on average worldwide. There is no estimate available so far of the damage the burning of the Amazon rainforest will have on the world’s air quality.
How bad is the situation in Pakistan?
A report published by the CNN last year showed that Pakistani citizens had the greatest exposure to atmospheric pollutants in the world after Bangladesh. Categorised as ‘unhealthy air quality’ by the US Air Quality Index, the country’s air had 74.27 micrograms per cubic meter of PM2.5 concentration.
In 2017, this level was 58 micrograms per cubic meter and the fourth highest in the world. To get an idea of the severity of the situation, the WHO’s least strict target is 35 micrograms per cubic meter. Pakistan has consistently exceeded this target since 1990.
Last year, WWF Pakistan Director-General Hammad Naqi Khan had said Lahore and Karachi were among the 10 most polluted cities in the world in terms of air quality. The thick blanket of smog that persisted in Lahore and increased hospitalisations were proof of that. Previous studies have linked air pollution in Karachi to deaths from heart diseases.
Currently, air quality monitoring only exists in four cities of the country: Islamabad, Lahore, Karachi and Peshawar. With no broad measures to control air pollution, and with the climate changing rapidly, things are only going to get deadlier.