Los Angeles is known for many things: Hollywood, beaches, celebrities, traffic, and smog. The city has long struggled with air pollution, especially ozone and particulate matter, which can cause health problems such as asthma, lung disease, heart disease, and premature death.
The main sources of air pollution in Los Angeles are motor vehicles, industry, power plants, and wildfires.
However, this spring and summer, Los Angeles residents have enjoyed some of the region's cleanest air in years, thanks to a persistent marine layer and cooler temperatures that have reduced the formation and spread of ozone.
According to the South Coast Air Quality Management District (AQMD), this year is tied for L.A.'s cleanest in the last decade based on the Air Quality Index (AQI), which measures the concentration of pollutants in the air.
The region has also recorded fewer days exceeding federal ozone standards this summer than usual.
But this respite may not last long, as climate change is expected to make air pollution worse in the future.
Higher temperatures, droughts, wildfires, and stagnant weather patterns can increase the levels and duration of ozone and particulate matter in the air.
Climate change can also affect human health and well-being in other ways, such as increasing the risk of heat-related illnesses, allergies, infectious diseases, and mental stress.
The consequences of air pollution
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Air pollution has significant consequences for society and the environment.
It can affect human health, safety, productivity, economy, culture, and quality of life. It can also affect ecosystems, biodiversity, water resources, soil quality, carbon cycle, and climate feedback, as per Phys.org.
According to a report by the American Lung Association (ALA), Los Angeles is the nation's smoggiest metropolitan area, ranking first for ozone pollution and fourth for particulate matter pollution.
The report estimates that more than 10 million people in Los Angeles are exposed to unhealthful levels of ozone or particulate matter each year.
The report also ranks Los Angeles as one of the most polluted cities in the world.
Ozone is a gas that forms when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react with sunlight and heat.
Ozone can irritate the eyes, nose, throat, and lungs; cause coughing, wheezing, and shortness of breath; aggravate asthma and other respiratory diseases; reduce lung function; increase susceptibility to infections; damage lung tissue; and increase mortality.
Particulate matter is a mixture of solid and liquid particles that are small enough to be inhaled into the lungs.
This type of matter can cause inflammation; impair blood circulation; increase blood pressure; trigger heart attacks and strokes; worsen diabetes; affect brain function; increase cancer risk; reduce life expectancy.
Air pollution can also affect the environment in various ways. It can reduce visibility; impair photosynthesis; alter cloud formation; affect rainfall patterns; modify atmospheric chemistry; increase surface temperature; reduce surface albedo; accelerate glacier melting; deposit acids or metals on soil and water; leach nutrients; damage vegetation.
Air quality management is a complex and multifaceted task that involves various actors and actions at different scales and stages, as per LA Times.
It requires coordination among governments, agencies, communities, businesses, researchers, media outlets.
It also requires emission reduction measures before pollution occurs; monitoring efforts during pollution events; mitigation actions after pollution episodes.
Air quality management faces many challenges in a changing climate. Some of these challenges are:
Increasing emission sources: Climate change can increase the emission sources of air pollutants by increasing temperature, evaporation, biomass burning, dust storms, and human activities such as energy use, transportation, and agriculture.
Limited emission controls: Emission controls such as regulations, standards, incentives, technologies, and behaviors are often insufficient or ineffective to reduce the emissions of air pollutants from various sectors such as transportation, industry, power generation, and residential.
Conflicting objectives: Air quality objectives may differ or conflict among stakeholders depending on their values, interests, priorities, and perspectives. For example, some may favor economic growth over environmental protection; others may favor individual freedom over collective responsibility; others may favor short-term benefits over long-term costs.
Uncertain outcomes: Air quality outcomes are influenced by many factors that are difficult to predict or control, such as weather, terrain, chemistry, transportation, human intervention. Air quality effects are also influenced by many factors that are uncertain or variable, such as exposure, sensitivity, response, adaptation, co-benefits, trade-offs.
Lack of knowledge: There is still a lack of scientific knowledge and data on some aspects of air quality science, air quality modeling, air quality monitoring, air quality communication, air quality education. There is also a lack of public awareness and understanding of air quality issues and solutions.
Climate change keeps making air pollution worse in Los Angeles, posing serious consequences and challenges for society and the environment.
Scientists call it the "new abnormal," as it is an ever-moving baseline of worse and worse conditions.
To address this problem, there is a need for more research, innovation, collaboration, communication, education, and action to prevent or reduce air pollution and exposure to it, and to adapt to the changing climate.
