Air Pollution: a global problem needs local fixes

Phoresta / 2019  / Air Pollution: a global problem needs local fixes

The Nature magazine published a column that faces the problem of air pollution and put forward some solutions. The authors are  Xiangdon Li, Ling Jin and Haidong Kan.

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The article is divided into two parts:  the first one is a detailed vision of the event – as we will see it has not been thoroughly analyzed – while in the second part there are some  passages that could lead to a mitigation of the problem. The basic thesis of this article is in the tile “Air Pollution:  a global problem that needs local fixes” Why? Xiandong Li gives an explanation in the first  sentences. Researchers must find the particles that are most dangerous to health in each place so policies can reduce levels of those pollutants first. The article is  mainly focused on China, and the author recalls a very striking, yet dramatic photo, where people perch on a high building to observe the heavy smog that enveloped the city of Zhengzhou in January 2017:  it’s a real siege… Then the article goes on with data, stating that each year, more than 4 million people die early because of outdoor air pollution, according to the World Health Organization (WHO). The main culprits are fine particles with diameters of 2.5 micrometres or less (PM2.5). These can penetrate deep into the lungs, heart and bloodstream, where they cause diseases and cancers. But global average estimates such as this assume that these particles are the same the world over. They are not: PM2.5 is a cocktail of chemicals (hydrocarbons, salts and other compounds given off by vehicles, cooking stoves and industry) and other, natural components such as dust and microorganisms. 

Levels of PM2.5 alone give only a rough guide to the toxicity of air pollutants in a particular place. Reducing PM2.5 by the same amount in different places will not deliver the same health benefits everywhere. To protect millions more lives, scientists need to help governments and municipalities to determine the most hazardous constituents of air pollution and mitigate them first. Researchers and policymakers need to rethink methods for assessing health risks and regulatory measures for reducing those risks. The mix — and its toxicity — varies from place to place and over time, in ways that are not tracked, understood or managed.  For example, in Asia, soot from residential heating and cooking is the biggest source of PM2.51.  In European countries, Russia, Turkey, South Korea, Japan and the eastern United States, agricultural emissions such as ammonia are the leading source. Desert dust boosts air pollution in northern Africa, the Middle East and central Asia. It is not clear which source is the most dangerous.

Levels of PM2.5 alone give only a rough guide to the toxicity of air pollutants in a particular place2. Reducing PM2.5 by the same amount in different places will not deliver the same health benefits everywhere. To protect millions more lives, scientists need to help governments and municipalities to determine the most hazardous constituents of air pollution and mitigate them first. Researchers and policymakers need to rethink methods for assessing health risks and regulatory measures for reducing those risks. We will discuss about this at a later time. (To be continued …)