ISLAMABAD                -             Scientists have found an association be­tween an increase in ozone exposure and short-term risk of death.

An international team of scientists has found an association between increased ex­posure to ozone and the short-term risk of death.

The findings, which appear in the BMJ, suggest that stricter air pollution policies would significantly reduce these deaths.

Ozone is a type of gas that consists of three oxygen atoms.

According to the United States Environ­mental Protection Agency (EPA), ozone has different health effects depending on where it comes from.

Stratospheric ozone helps shield life on Earth from the sun’s ultraviolet radiation and, as such, is a benefit to human health.

However, ground-level ozone (GLO) has associations with a variety of health issues. It is especially dangerous for older people, children, and people with diseases of the lungs, such as asthma. According to the EPA, GLO forms when pollution reacts with sun­light. This pollution is produced through combustion, overwhelmingly from hu­man-created sources that burn fossil fuels, such as vehicles and power plants.

According to the authors of the study, “ozone levels are predicted to increase with global warming,” and, as such, experts must gain a full understanding of the relationship between GLO and health issues.

The authors of the study note that while many studies document the adverse health effects of ozone exposure, they do not often address the increase of short-term deaths it causes. Instead, studies have typically focused on longer-term general adverse health issues.

Quantifying the short-term effects of ozone exposure can be helpful when it comes to forming a policy on air pollution.

This is especially important given that air-pollution policies differ significantly around the world.

According to the article in the BMJ, the World Health Organization (WHO) suggest an ozone threshold of 100 micrograms per cubic meter of ambient air (100 ?g/m3), the European Union (EU) put that figure at 120 ?g/m3, the United States suggest 140 ?g/m3, and finally China recommends 160 ?g/m3.

By understanding the effects of GLO on short-term deaths, the study’s authors hope that consistent and evidence-based policy will be able to save a significant number of lives around the world.

The international team looked at data from 406 cities in 20 countries, focusing on the number of deaths and daily environmen­tal effects. They covered a period between 1985 and 2015. By identifying the daily aver­age ozone levels, the types of particulate, the ambient temperature, and the humidity at each of the locations they covered, they were able to identify a possible association be­tween changes in ozone levels and short-term deaths. The team found that an increase of 10 ?g/m3 in the ozone over two days resulted in an increased risk of death by 0.18%.

This equates to 6,262 additional deaths in the cities they studied attributable to ozone air pollution.

Drawing on data from the World Health Organisation (WHO), the team notes that over 80 per cent of people who live in an ur­ban area where authorities record air pol­lution levels are exposed to higher air pol­lution levels than the WHO’s recommended threshold of 100 ?g/m3.