BMJ: more than 45 million people in 406 cities in 20 countries study that exposure to ozone pollution every day may increase the risk of death

February 12, 2020 / BIOON / -- recently, an international magazine published in BMJ In the study report above, scientists from London School of health and tropical medicine and other institutions found that daily sampling exposure to the ground was related to the increased risk of death in more than 400 cities in 20 countries Relevant research results show that if countries implement the most stringent air quality standards, 6000 deaths can be avoided every year Photo source: cc0 public domain ground level Ozone) is a kind of highly active gas, which is common in urban and suburban environment When pollutants react in sunlight, ozone will form The current air quality thresholds (in micrograms per cubic meter of ambient air) are 100ug / m3 (who), 120ug / m3 (EU standard), 140ug / m3 (US national ambient air quality standard) and 160 UG / m3 (China air quality standard) Recent research results show that 80% of the world's urban population is exposed to air pollution levels that exceed the World Health Organization threshold Previous research results have revealed a positive correlation between ground ozone and human mortality However, due to differences in design and quality, it is difficult for researchers to reach consistent conclusions in different regions To solve this problem, researchers divided into The death toll and environmental measures, such as weather and air pollutants, were analyzed in 406 cities in 20 countries from 1985 to 2015 Using data from cooperative research networks in multiple cities and countries, the researchers obtained the daily average ozone level (the highest background level is 70 UG / m3), particulate matter, temperature and relative humidity at each location to assess the additional deaths per day due to ozone exposure The researchers analyzed a total of 45165171 deaths in 406 cities On average, if the ozone concentration increased by 10 UG / m3 on the same day and the previous day, the death risk of the population would increase by 0.18%, which revealed the potential direct causal relationship between the two This is equivalent to that if 406 cities follow the most stringent air quality standards implemented by the World Health Organization, it is possible to avoid an annual increase of 6262 deaths in 406 cities, which accounts for 0.2% of the total mortality rate The researchers said that even if the ozone concentration is lower than the World Health Organization guidelines, the impact on human mortality is relatively small, but it is still noteworthy, which supports the World Health Organization to encourage countries to review the current air quality guidelines and strengthen emission restrictions to meet these recommendations This is an observational study At present, researchers are unable to determine the causal relationship between the two At the same time, researchers put forward some limitations, such as South America, Africa and the Middle East, which are not effectively assessed Moreover, differences in monitoring and data collection between different countries may also affect the accuracy of their assessment Nevertheless, the results of this study show that, according to more stringent air quality standards, the mortality rate of people related to ozone may also decline; in addition, further interventions to reduce ozone pollution may also bring additional health benefits to people, even in areas that meet current regulatory standards and guidelines Finally, the researchers said that the results of this study are of great significance for the design of future public health actions, such as the implementation of relevant mitigation strategies to reduce the impact of climate change Original sources: Ana m Vicedo Cabrera, Ben Armstrong, Eric Lavigne, et al Short term association between ozone and moritality: Global two stage time series study in 406 locations in 20 countries, BMJ (2020) Doi: 10.1136/bmj.m108