Air Pollution Alert: July's Worst Day

Fireworks are a staple of Fourth of July celebrations in the United States, but they also contribute to a significant increase in air pollution. The smoke and waste generated by fireworks can cause a range of respiratory and cardiovascular health issues, including asthma, lung cancer, and heart attacks. In recent years, air quality alerts have been issued in various parts of the country, urging residents to limit their exposure and take precautions to protect their health. With millions of fireworks set off each year, the impact of these celebrations on air quality and public health is a growing concern.

Fireworks displays cause air pollution

Fireworks displays are a well-loved tradition in many countries, but they come at a cost: they cause air pollution and negatively impact air quality. This is especially true around the 4th of July, when fireworks are often set off as part of Independence Day celebrations in the United States.

The smoke and particles released from fireworks can contain harmful chemicals and metals, including arsenic, cadmium, lead, and thallium. These substances can have detrimental effects on human health, ranging from minor issues such as coughing to more severe consequences like asthma, cardiovascular disease, and even heart attacks in individuals with pre-existing heart conditions. The brilliant colours in fireworks are created using powdered metallic salts, with copper producing blue, barium yielding green, and strontium resulting in red hues.

The impact of fireworks on air quality has been observed and measured by various organisations. For instance, the U.S. Environmental Protection Agency's AIRNow program collects real-time data from over 1400 air quality sites across the country. On the 4th of July in 2024, many readings reached at least the moderate stage, with some communities in the Midwest and along the West Coast even reaching levels classified as very unhealthy. Similarly, a study published in the journal Atmospheric Environment found that fireworks released 42% more pollutants into the air on the 4th and 5th of July compared to a typical day. This includes a spike in perchlorate emissions, which can potentially disrupt the thyroid's hormone production.

The Wisconsin DNR has also monitored spikes in fine particle (PM2.5) concentrations during and after fireworks displays. Nitrogen and sulfur, used for colour and special effects, can form nitric and sulfuric acids upon combining with oxygen, posing risks to lung health. While the smoke generally dissipates within a few hours, vulnerable individuals, including children, the elderly, and those with respiratory or cardiac conditions, may experience lingering health effects.

To mitigate the air pollution caused by fireworks displays, some cities and organisations have explored alternative celebration methods. For example, some cities have implemented drone light shows as a substitute for traditional fireworks, offering a safer and more environmentally friendly option. By recognising the impact of fireworks on air quality and taking proactive steps to reduce their use, we can strive for healthier and more sustainable celebrations.

Health effects of air pollution

Air pollution is a serious issue that poses significant risks to human health, with a range of adverse effects on the body. It is the leading environmental cause of premature death, with over 4 million people dying prematurely each year due to outdoor air pollution. The day in July with the highest air pollution levels can vary, but fireworks on Independence Day, July 4th, have been known to cause a significant drop in air quality. For example, in 2024, air quality readings across the United States dropped into the moderate to unhealthy range due to firework displays.

One of the most concerning health effects of air pollution is its impact on the respiratory system. Air pollution can irritate the respiratory tract, causing coughing, throat irritation, and chest pain. Prolonged exposure to air pollution can lead to chronic bronchitis, decreased lung function, and an increased risk of respiratory infections. Fine particles (PM2.5) in the air can penetrate deep into the lungs, causing asthma, bronchitis, and an increased risk of lung cancer.

Air pollution also has significant cardiovascular effects. The tiny particles in air pollution can enter the bloodstream and cause inflammation, increasing the risk of heart disease, heart attacks, irregular heartbeats, heart failure, and strokes. Black carbon, a component of particulate matter, is of particular concern as it is associated with an increased risk of heart attacks, strokes, and hypertension.

Additionally, air pollution has been linked to adverse pregnancy outcomes. Exposure to air pollution can increase the level of toxic chemicals in a pregnant woman's blood, stressing her immune system and potentially leading to preterm birth or low birth weight. Research also suggests that air pollution can negatively impact brain development in children, with higher exposure to PM2.5 being a potential factor.

The effects of air pollution are not limited to physical health. Studies have found a strong link between air quality and mental health. People living in areas with poor air quality have higher rates of bipolar disorder and major depression. Additionally, non-physical stressors such as poverty, racial/ethnic discrimination, and residency status can amplify the harmful effects of air pollution on mental health.

Overall, air pollution has far-reaching consequences for human health, contributing to a range of physical and mental health issues. It is important for individuals to be aware of their local air quality and take steps to protect themselves from the harmful effects of air pollution.

Air quality warnings

In July, particularly around July 4th in the United States, air pollution can spike due to firework displays during Independence Day celebrations. Fireworks emit high levels of particle pollution, including heavy metals and chemicals such as perchlorate, arsenic, cadmium, lead, and thallium. These pollutants can have significant health impacts, including respiratory and cardiovascular issues, and can increase the risk of developing asthma, lung cancer, and other respiratory diseases.

During periods of poor air quality, it is crucial to follow official recommendations to minimise exposure and protect your health. These recommendations include limiting outdoor activities and staying indoors with windows and doors closed. Running air conditioning or using an air purifier can also help improve indoor air quality. It is essential to avoid physical exertion, especially in areas with high levels of air pollution, as it can increase the amount of polluted air inhaled.

In recent years, some communities in the United States have taken steps to address the issue of firework-related air pollution. For example, in 2024, air quality readings on July 4th showed that many locations across the country reached at least the moderate stage of air pollution, with some areas even reaching levels considered very unhealthy. As a result, cities like Seattle urged residents to leave fireworks at home this year, with the Seattle Fire Department banning them within the city limits.

While fireworks are a significant contributor to air pollution in July, it is important to note that other factors can also impact air quality during this month. Wildfires, for instance, can send pollution high into the atmosphere, causing it to spread over vast distances. The combination of wildfire smoke and firework emissions can further deteriorate air quality, as seen in Seattle in 2023.

Overall, air quality warnings in July, especially around Independence Day in the United States, are crucial to safeguard public health. By raising awareness, providing recommendations for reducing exposure, and implementing measures to mitigate air pollution, communities can work towards improving air quality and protecting the well-being of their residents.

Air pollution from wildfires

While I could not find specific information about air pollution in July, wildfires are a significant contributor to air pollution and are known to occur in July. For example, in 2018, San Diegans received cell phone notifications warning of poor air quality in San Diego on July 5. Similar warnings were issued in 2017 and 2016 around the same time.

Wildfires are one of the largest sources of black carbon, a super pollutant that has driven half of global warming to date. Black carbon intensifies heatwaves, alters weather patterns, accelerates the melting of ice and snow, and perpetuates the cycle of climate change and extreme wildfires. For example, the East Siberian wildfires from 2019 to 2021 accounted for elevated black carbon levels in the Arctic, and the Amazonian fires increased glacier melting by an estimated 3-4%.

Wildfires release a range of pollutants into the atmosphere, including black carbon, carbon monoxide, nitrogen oxides, mercury and other heavy metals, and particulate matter. These pollutants can combine with existing air pollution, further increasing the harmful effects on human health and the environment. The smoke from wildfires can drift for thousands of miles, bringing air pollution to areas far from the fire.

Particulate matter poses a significant health risk as these fine particles can easily enter the respiratory system, causing respiratory issues, aggravating existing conditions like asthma, and increasing the risk of heart and lung diseases. A 2021 study found that wildfire smoke caused over 33,000 deaths in a single year across 43 countries. Wildfire smoke can also have widespread impacts on the atmosphere, affecting cloud formation, precipitation, and the distribution of solar radiation reaching the Earth's surface, which can lead to changes in temperature and atmospheric stability.

The relationship between air pollution, climate change, and wildfires is a vicious cycle. Burning trees release carbon and particulate matter, causing air quality to plummet. Human activities, such as burning fossil fuels, transportation, and industrial processes, release greenhouse gases and black carbon emissions, which fuel climate change and contribute to more frequent and intense wildfires. Addressing super pollutants, such as black carbon, through interventions with long-standing, sustainable impacts, is critical to breaking this cycle.

Plastic pollution from fireworks

Fireworks are a source of wonder and joy for many people, but they are also a significant source of air pollution. On the 4th of July, firework displays across the United States heavily impact air quality readings for many cities. The Air Quality Index (AQI) often drops into the moderate, unhealthy, and even very unhealthy ranges due to the smoke and microscopic particles released by fireworks.

While paper is a common material in fireworks, plastic is also used in their construction. This creates a dangerous mix of debris that can injure humans, pets, and wildlife. Plastic casings and non-biodegradable materials contribute to environmental litter and pose ingestion risks to animals. The cumulative effects on wildlife are notable, with birds abandoning nests, mammals experiencing panic reactions, and even invertebrates showing altered behaviours in response to the loud noises and chemical residues left behind.

The combustion of fireworks releases a host of toxic contaminants that affect air quality and contribute to climate change, including carbon dioxide, carbon monoxide, nitrogen, sulphur dioxide, and particulate matter. These pollutants can also settle on soil and water, altering soil nutrients and increasing water acidity, with severe consequences for ecosystems. Fireworks also produce light pollution, which can disrupt ecosystems by affecting animals' sleep patterns, migration, and ability to find food and reproduce.

The environmental impact of fireworks has led some places to seek alternatives, such as laser light shows, biodegradable fireworks, and the purchase of carbon offsets. Cities like Zhengzhou in China have implemented policies prohibiting fireworks to improve air quality. With the awareness of the ecological footprint of fireworks, there is a growing call for change to minimise their effects, especially in the context of climate change.

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