California's Coast: Impacted By China's Air Pollution?

Air pollution from China is a pressing issue, with the country being one of the greatest emitters of air pollution globally. Trans-Pacific air pollution from China, including sandstorms and industrial emissions, has been shown to impact air quality and health in California. The west coast of the United States is particularly vulnerable due to prevailing winds from the Pacific Ocean. While China's pollution primarily affects its neighbouring countries, studies have found evidence of its impact on the western United States, including California.

Trans-Pacific air pollution from China

California, being on the West Coast, is particularly vulnerable to trans-Pacific air pollution from China. Powerful global winds, known as "westerlies," can carry air pollutants from China across the Pacific Ocean to the United States. These pollutants include ozone, carbon monoxide, mercury, nitrogen oxides, and particulate matter. The composition of dust particles in California has been found to match that of the Gobi Desert and other Asian sites, further supporting the notion that air pollution from China reaches the West Coast.

The impact of trans-Pacific air pollution from China on California is twofold. Firstly, it affects the air quality in the state, leading to an increase in smog and haze. For example, Los Angeles experiences extra days of smog that exceed federal ozone limits due to pollutants from Chinese factories. Secondly, it has implications for public health. Studies have shown that heavy sandstorms in China are associated with a modest increase in acute respiratory disease hospitalizations in California.

The problem is exacerbated by the production of goods in China for export to the United States. This dynamic has been termed the "hidden price" of outsourced manufacturing, as American consumers bear the environmental impacts of air pollution generated during production. Researchers have emphasized the need for international cooperation to address this issue, highlighting the interconnectedness of global economies and emissions.

To summarize, trans-Pacific air pollution from China is a significant concern for California. It affects both the air quality and the health of California's residents. As China continues to develop and produce goods for the global market, the impact of its air pollution on the western United States is likely to persist and possibly intensify. Addressing this issue will require a global approach and collaboration between nations to improve air quality and mitigate the environmental impacts of economic activities.

The impact on morbidity in California

California's air quality is affected by air pollution from China, which is transported across the Pacific Ocean. This trans-Pacific pollution is a result of the production of goods in China for export to the United States and global consumer demand for these goods.

China is one of the greatest emitters of air pollution in the world, and its rapid economic growth has led to increased consumption of fossil fuels, contributing to worsening air quality in California. While most air pollution in U.S. cities is generated locally, it is estimated that nearly 25% of the particulate matter in the sky above Los Angeles on certain days can be traced back to China. Some experts even predict that China could eventually account for a third of California's air pollution.

The impact of this intercontinental air pollution on morbidity in California has been studied, with a focus on patients with respiratory and heart disease between 2005 and 2012. The research found that heavy sandstorms in China were associated with a modest increase in acute respiratory disease per capita in California, representing 0.5-4.6% of average weekly hospitalizations. However, no significant effect on morbidity in California was found during the Chinese New Year, a 7-day national holiday.

The results of these studies suggest that policymakers in California should prepare for potential changes in air quality following major sandstorms in China, as the state is particularly vulnerable to winds carrying pollution from across the Pacific Ocean. While foreign pollution emissions are not currently addressed by the U.S. Environmental Protection Agency's regulations, these findings highlight the need for a global approach to preserving air quality and mitigating the harmful effects of air pollution on human health.

The impact on PM10 and PM2.5 in California

California's air quality is affected by intercontinental air pollution from China. Powerful global winds known as "westerlies" can push airborne chemicals across the Pacific Ocean in days, causing dangerous spikes in contaminants.

A study by Jacob et al. (1999) found that trans-Pacific ozone could potentially offset reductions in domestic anthropogenic reductions of ozone. Ewing et al. (2010) found that 29% of lead, an indicator of industrial pollution, in San Francisco was derived from Asia. Another study by Dan Jaffe, an atmospheric scientist, detected ozone, carbon monoxide, mercury, and particulate matter from Asia at monitoring sites in Oregon and Washington State.

The Environmental Protection Agency estimates that on certain days, nearly 25% of the particulate matter in the sky above Los Angeles can be traced to China. Some experts predict that China could one day account for a third of California's air pollution.

The impact of this intercontinental air pollution is particularly felt in the levels of PM10 and PM2.5 in California. PM10 and PM2.5 refer to particulate matter with an aerodynamic diameter of less than 10 micrometres and 2.5 micrometres, respectively. These fine particles can have significant health impacts, especially on respiratory and cardiovascular systems.

Studies have shown that heavy sandstorms in China are associated with a modest increase in acute respiratory disease in California, representing 0.5-4.6% of average weekly hospitalizations. While there is no significant effect on morbidity from the Chinese New Year, a 7-day national holiday, sandstorms are a naturally occurring phenomenon that can have a more pronounced impact on air quality.

The sources and composition of PM10 and PM2.5 pollution from China vary. About a third of Asian pollution is dust, which is increasing due to drought and deforestation. The rest is composed of sulfur, soot, and trace metals from the burning of coal, diesel, and other fossil fuels.

The impact of these pollutants on California's air quality is complex and dynamic, influenced by various factors such as wind patterns, geographical location, and the interaction with local pollution sources. While California also has local pollution sources, the transboundary nature of air pollution from China adds a layer of complexity to managing air quality and protecting public health in the state.

The impact of Chinese New Year

Air pollution from China is impacting California, and the west coast of the United States more generally. This is due to a combination of factors, including the prevailing winds coming from the Pacific Ocean, the increase in manufacturing and consumerism in China, and the country's position as one of the greatest emitters of air pollution globally.

Several studies have found that a significant amount of the air pollution in California can be traced back to China. For example, a 2014 study by nine scholars based in three nations found that the movement of air pollutants from the manufacturing of goods in China for the American market has resulted in a decline in air quality in the Western United States. This study also explored the environmental consequences of interconnected economies, highlighting that outsourcing production to China does not relieve consumers in the United States from the environmental impacts of air pollution.

Another study, published in 2015, found that China's contribution to air pollution on the West Coast of America had offset nearly half of what should have been a 2% drop in pollution levels. This was attributed to a 21% rise in ozone-forming pollutants emitted by car tailpipes and coal plants, driven by the robust Chinese economy during the six years studied.

Overall, the impact of Chinese New Year on air pollution in California is complex and influenced by various factors, including the prevailing winds, the level of pollution in China, and the timing of the holiday in relation to other factors affecting air quality and health in California.

The impact of sandstorms in China

China is one of the countries most affected by dust-sand storms and desertification (DSSD). The country's northwest, north, and northeast regions are particularly vulnerable to sandstorms, which originate mainly in the Gobi and Taklamakan deserts. In 2023, a series of sandstorms affected over 500 million people in these regions, leading to violent weather, including powerful winds of up to 92 mph that felled trees, crushed cars, and damaged buildings. To combat the issue, Beijing has had to cancel flights and close public parks to ensure the safety of its citizens.

Sandstorms have a significant impact on air quality, and their effects can be felt beyond China's borders. Studies have shown that trans-Pacific air pollution from China affects air quality and morbidity in California. For instance, a large sandstorm in the Gobi Desert in April 2013 caused a haze in Owens Valley, California, a few days later. Additionally, research has linked an increase in acute respiratory disease hospitalizations in California to heavy sandstorms in China, with a 0.5-4.6% rise in per capita weekly hospitalizations.

China's air pollution, exacerbated by sandstorms, has far-reaching consequences. The country's rapid economic growth, reliance on coal-fired power plants, and soaring car ownership contribute to its position as one of the world's largest emitters of air pollution. This pollution knows no borders, regularly affecting the air quality in neighboring countries like South Korea and Japan. Trans-Pacific air pollution from China has been detected in the Western United States, with some experts predicting that China could eventually account for a third of California's air pollution.

The environmental and health impacts of China's sandstorms and air pollution are significant. The direct economic losses caused by desertification in China are estimated at US$7.7 billion annually, and the pollution's effects on morbidity and respiratory health in the US are concerning. As a result, policymakers in California may need to consider the impact of China's sandstorms when planning for and regulating air quality to protect public health.

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