The current air quality emergency in Delhi, where the AQI has reached 999 (which is well above the “safe” level of 100 set in the US by the EPA), has raised recent awareness about air pollution and human health.
I recently shared some articles on the #DehliAirEmergency on my social feeds, adding a comment about how air pollution caused over 8 million deaths per year. Several people reached out to me, surprised that air pollution could cause death or chronic illness, and so I thought I’d devote a post to address the health impacts of air pollution.
I must say I myself was shocked to learn about the serious and sweeping dangers of air pollution. I always assumed it could cause some respiratory distress, but didn’t think it could do much more than that.
Then, I took a job where I spent a semester researching air pollution as a justice issue for a lawyer at Mailman (she’s a legend and I learned so much…but that’s another story for another time) and I was surprised to learn it caused not only respiratory illness, but also cardiovascular diseases, cancer, neurological illnesses, and even death.
What’s alarming about air pollution, and many other environmental health exposures, is that they are, for many, unavoidable. While we can choose whether or not we smoke, do drugs, or engage in other risky health behaviors, we must all breathe air, we do not have the luxury of choosing how clean or dirty that air is.
Obviously, air pollution levels vary by geographical location, and there are luxuries afforded to privileged individuals to reduce their risks. However, air pollution, like climate change, is a threat to us all.
I hope by spreading awareness about these topics I can help others understand how and why we need to take action. I don’t think anyone wants their family, friends, and pets breathing in toxic air, because as you will learn in the text that proceeds this, air pollution can do a lot of damage to health.
So with all that said, here’s a post about how air pollution can impact human health. I hope you enjoy it As always, please feel free to leave questions or comments below, and/or reach out to me on Instagram, Twitter, or YouTube!
What is air pollution?
Air pollution is a mixture of natural and human-created substances in the air. According to the WHO, the 6 major air pollutants include ground-level ozone, particle pollution (read all about PM 2.5 here), carbon monoxide, sulfur oxide, nitrogen oxides and lead.
Air pollutants are typically divided into two main categories: outdoor air pollution, and indoor (ambient) air pollution.
Outdoor air pollution is, as the name suggests, pollution you would be exposed to the outside of the built environment, and includes things like fine particles produced by the burning of fossil fuels, ground-level ozone (which is produced from the reaction of oxygen and urban smog), tobacco smoke, and noxious gasses such as sulfur dioxide, nitrogen oxides, carbon monoxide, and chemical vapors.
Indoor air pollution (also known as ambient or household air pollution) is found within buildings and homes and is considered one of the most important environmental health risks worldwide.
Indoor air pollution involves exposure to household particles like building materials such as asbestos, formaldehyde, and lead, allergens from pests like cockroaches and mice, tobacco smoke, mold, and pollen. Indoor air pollution may also contain carbon monoxide, radon, and household products and chemicals found from cleaning, building, or pest control products.
In developing countries, indoor air pollution is often generated by incomplete combustion of fuels for cooking, heat, and lighting, without ventilation. Coal, charcoal, wood, kerosene, and dung are commonly burned using ‘dirty’ technologies, which do not completely burn these fuels, and emit air pollution into the home. People who spend more time around the source of the air pollution, like women and children, are at highest risk for adverse health effects.
Both forms of air pollution are important to address and both can contribute to each other.
Air Pollution and Human Health: How many people die each year from air pollution?
Air pollution is responsible for an estimated 8 million deaths each year (some estimates go up to 8.8 million deaths per year), with about 4 million of those deaths coming from indoor air pollution.
Yes, you read that correctly – over 8 million people die from air pollution each year.
To put that in perspective, the WHO estimates 7 million smokers die each year from cigarettes (and an additional 1.2 million die from secondhand smoke), meaning deaths from air pollution are roughly on par with deaths from smoking. Except individuals have the choice to smoke. AIr pollution is something people can’t escape.
But how does air pollution kill people? And how does it make them sick?
Air pollution and human health, explained:
Different long and short-term exposure to air pollution can lead to different adverse health outcomes. There is also more recent interest in the long-term effects pre and perinatal (meaning during the few first weeks of life) exposure to air pollution.
The resulting illness and its severity is dependent upon the exposure length, pollutant, and individual susceptibility, among other things.
When most people think of air pollution causing a health impact, they think of respiratory distress. Indeed, air pollution can cause a variety of respiratory illnesses, including wheezing, coughing, dry mouth, and breathing difficulties.
For those with pre-existing asthma, exposure to air pollution may make symptoms worse.
Cardiovascular disease is the number one killer in the United States, and air pollution is considered an independent risk factor for cardiovascular disease.
Particles inhaled in polluted air can make their way into the bloodstream, cause oxidative stress, and induce systemic inflammation in peripheral circulation. This causes irregular heartbeat, stroke, aggravation of existing heart conditions, and heart attacks.
CO, lead, and SO2 exposure may also lead to cardiovascular changes and aggravation of existing cardiovascular disease.
After an extensive review in 2013, the International Agency for Research on Cancer determined there was evidence to state air pollution can cause cancer in humans.
Long-term exposure to certain pollutants can cause DNA injury, DNA adduct formation, chromosomal aberrations, and modifications in DNA methylation, meaning DNA is insulted and may not be able to repair itself, which increases the risk of cancer.
There is strong epi evidence to suggest that air pollution is directly associated with increased rates of lung cancer. More recent data also suggests that air pollution is associated with increased risk of mortality from other types of cancer, including liver, breast, and pancreatic cancers.
Air pollution in megacities has also been associated with anxiety and aggression.
Furthermore, carbon dioxide (CO) is one of the 6 major pollutants. CO preferentially binds to hemoglobin (which normally carries oxygen in the body), and decreases the amount of oxygen your hemoglobin is able to carry to various tissues in the body, including the brain. This may lead to CO poisoning.
Symptoms of CO poisoning include headache, dizziness, weakness, nausea, and in some cases, loss of consciousness.
Pregnancy and air pollution:
Chemicals found in air pollution can pass through the placenta and amniotic fluids, meaning they can reach the developing fetus.
Research on prenatal exposure to air pollution suggests maternal exposure to air pollution is associated with adverse birth outcomes, including low birth weight, small for gestational age infants, intrauterine growth restriction, and preterm birth.
Exposure to air pollution within the first few weeks of life increases risks of lung developmental defects, which may lead to reduced lung function in child and adulthood.
Who is most vulnerable to air pollution?
Children are especially susceptible to air pollution and other inhalation exposures, as they have a more frequent rate of respiration than do adults. Their lungs are still developing, further increasing their vulnerability.
Elderly adults with lung diseases (diagnosed or undiagnosed) are also at high risk. Individuals with existing lung and cardiovascular diseases are more vulnerable to the impacts of air pollution, which may exacerbate their symptoms and conditions.
Importantly, aiIr pollution disproportionately impacts individuals in already marginalized groups. Often times, impoverished populations live in densely populated cities with poor air quality regulations.
Furthermore, pollution-producing manufacturing facilities have been found to be more likely to be placed by lower-income neighborhoods than by higher-income neighborhoods, placing those with fewer resources at an even greater risk of falling ill from the effects of air pollution.
What causes air pollution?
Air pollution comes from four main sources: Mobile sources, which include cars, buses, planes, trains, and trucks, stationary sources, such as oil refineries, industrial facilities, and power plants, area sources, such as agricultural areas, cities, and wood burning fireplaces, and natural resources, such as wildfires, volcanoes, and wind-blown dust.
Humans are responsible for producing the majority of air pollution. Although volcanic eruptions and other natural events do contribute small amounts of pollution to the air, the air pollution crisis is driven by human combustion of fossil fuels and the emission of greenhouse gases. According to the EPA, the top contributor to air pollution in the US is from automobile sources.
How can I protect myself from air pollution?
No one can fully escape being exposed to air pollution. There are some things you can do to reduce some of your exposure in certain situations. If you are concerned about your air quality, an indoor air filter (see the EPA air cleaner and filter guide here) and/or use a N-95 or P-100 respirator (the state of California has a useful guide for using these masks correctly for air pollution from wildfires) may help.
If you currently burn things inside your home, including cigarettes, candles, or fires, reconsider your actions, or at the very least, ensure you have adequate ventilation.
If the air quality is poor outside (see this article to learn how to check your local air quality, and understand what it means when your phone says ‘unhealthy air quality for sensitive groups’), avoid spending time outdoors, and refrain from engaging in physical activity outside, as it increases respiration rate, and therefore, your exposure to air pollution.
You can also consider taking steps to reduce your contribution to air pollution by using more eco-friendly or public transportation options, quitting or avoiding starting to smoke, refraining from burning dirty fuels such as dung, coal, or kerosene, and reducing your use of electricity, which may come from the burning of fossil fuels.
And, if you really want to reduce air pollution in a meaningful way, start to advocate for policies that support protecting our air quality and our environment. Join campaigns that support clean air. Use your votes to support regulatory environmental regulatory policies and the politicians that support them. Offer comments on public forums about air quality and regulations. Educate your neighbors about air pollution, its dangers, and how they can also advocate to improve air quality.
This is the best way to make significant changes. As someone who is typing this on a laptop I can’t tell you that it’s possible to eliminate air pollution, as I myself am using power right now, which inevitably burns fossil fuels and contributes to air pollution.
However, I hope by offering awareness and resources about air pollution and human health, I can inspire you to take action in whatever way you can to protect yourself, your friends, your pets, and your family from the dangers of air pollution!