Air pollution is a well-known problem for our health and the environment. We recognize it when we see brown haze over a city, smoke from busy roads, or pollution from factories. Sometimes we can’t see air pollution, but we can smell it.
Air pollution is a big danger to our health and well-being. It causes over 6.5 million deaths each year worldwide, and this number has been going up in the last 20 years.
What Is Air Pollution?
Air pollution is made up of harmful substances from both human activities and natural sources.
Human-made air pollution comes from things like car exhaust, heating homes with fuel oils and natural gas, factories, power plants that burn coal, and chemical production.
Nature also releases harmful substances into the air, such as smoke from wildfires (often caused by people), ash and gases from volcanoes, and gases like methane from decomposing plants and animals in the soil.
Traffic-Related Air Pollution (TRAP) is a mix of gases and particles from cars and trucks. It includes ground-level ozone (smog), different kinds of carbon, nitrogen oxides, sulfur oxides, volatile organic compounds, polycyclic aromatic hydrocarbons, and fine particulate matter.
Ground-level ozone, often called smog, forms when pollutants from cars, power plants, industrial boilers, and refineries react in sunlight.
Harmful gases include carbon dioxide, carbon monoxide, nitrogen oxides (NOx), and sulfur oxides (SOx). These come from car emissions and industrial processes.
Particulate matter (PM) consists of tiny chemicals like sulfates, nitrates, carbon, or dust. It comes from car and industrial emissions, cigarette smoke, and burning organic matter like wildfires. Fine particulate matter (PM 2.5) is very small, about 30 times thinner than a human hair. It can get deep into the lungs and cause health problems. PM 2.5 is the main cause of health issues from air pollution in the U.S.
Volatile organic compounds (VOCs) are chemicals that easily become vapors or gases. They come from things like paints, cleaning supplies, pesticides, some furniture, and craft materials like glue. Gasoline and natural gas are major sources of VOCs, which are released during burning.
Polycyclic aromatic hydrocarbons (PAHs) are organic compounds made of carbon and hydrogen. There are over 100 types of PAHs in the environment, and 15 are known to cause cancer. They are produced by burning and by industrial processes like making iron, steel, and rubber products, as well as power generation. PAHs are also found in particulate matter.
Air Pollution and Climate Change
Air pollution and climate change are connected and affect each other in complex ways in the atmosphere. Both air pollution and climate change mainly come from the same sources, like burning fossil fuels. These problems are big threats to people’s health and the environment all over the world. To learn more, check out Health Impacts of Air Quality.
What is NIEHS doing?
For over 50 years, NIEHS has been a leader in studying air pollution. The institute still funds and does research on how air pollution affects health and which groups of people are most affected.
Air pollution Affects the Most
Air pollution affects everyone, but some groups are hurt more. Nearly 9 out of 10 people living in cities around the world are affected by air pollution.
Research funded by NIEHS shows that air pollution hits certain races, ethnic groups, and people with lower incomes harder. Air pollution levels have gone down over the years, but not equally for everyone. People who earn more than $70,000 a year have seen bigger drops in pollution from factories, energy, transportation, homes, and businesses compared to people with lower incomes.
Children
The NIEHS-funded Children’s Health Study at the University of Southern California is one of the biggest studies on how air pollution affects children’s lungs over time. Here are some of their findings:
- High air pollution levels lead to more short-term lung infections, causing kids to miss more school.
- Children who play many outdoor sports in areas with high ozone are more likely to get asthma.
- Kids living near busy roads have a higher risk of getting asthma.
- Kids with asthma who are around high levels of air pollution are more likely to show symptoms of bronchitis.
- Living in areas with high pollution can cause lung damage in children.
Older Adults
Alzheimer’s disease and other dementias are big problems for older people. Researchers at the University of Washington found that air pollution can increase the risk of these diseases. However, a study in 2022 showed that better air quality can lower the risk of dementia in older women, making them feel almost 2 1/2 years younger.
Air pollution has also been linked to other brain disorders like Parkinson’s disease. A study looked at hospital records of 63 million older adults in the U.S. from 2000-2016 and found that areas with high PM2.5 levels had more cases of these diseases.
For older adults, long-term exposure to traffic-related air pollution (TRAP) can lead to physical disabilities, especially among racial minorities and people with lower incomes. Air pollution can also cause bone damage in postmenopausal women, especially in the spine.
Eating omega-3 fatty acids, found in some fish, may help protect older women’s brains from damage caused by PM2.5.
Villagers
A research project supported by NIEHS aimed to improve health for children with asthma in rural areas. They found that some farming practices make air quality worse and contribute to asthma. They used HEPA air cleaners and home education programs to reduce kids’ exposure to pollutants.
In rural areas, burning agricultural waste can harm children’s lungs, even with just two weeks of exposure per year. This burning is a cheap way to clear crop leftovers, but it’s harmful to kids’ health.
Large animal farms in rural areas can also pollute the air with ammonia gas, causing lung problems in children with asthma.
NIEHS and Community Involvement
NIEHS supports community involvement in research to address health concerns. For example, in Imperial County, California, residents use 40 community-run monitors to track air pollution. Improvements in air quality here have led to better lung function in children.
NIEHS grant recipients have developed ways to reduce exposure to TRAP in communities, such as:
- Using HEPA filters.
- Building land-use buffers and planting trees.
- Designing urban areas with parks and gardens.
- Creating safe walking and biking paths.
Air pollution affects our health
Breathing in polluted air can harm our cells and cause problems like chronic diseases and cancer. In 2013, the World Health Organization (WHO) said that air pollution can cause cancer.
Many people die because of air pollution. A harmful air pollutant called PM2.5 increases the risk of death.
Researchers, with help from NIEHS, found that fewer people died after new air pollution rules were made and coal power plants were shut down. They studied this for 21 years. They found that PM2.5 from coal was twice as dangerous as PM2.5 from other sources. This is because coal PM2.5 has more sulfur dioxide, black carbon, and metals.
Air pollution can cause cancer, heart disease, lung diseases. Diabetes, obesity, and problems with the brain and immune system.
Research on air pollution and its health effects is always growing and improving.
Cancer
A big study of over 57,000 women found that living near busy roads might increase a woman’s risk of getting breast cancer. The NIEHS Sister Study also found that breathing in toxic substances like methylene chloride. Which is found in spray products and paint removers, can raise the risk of breast cancer.
Being around benzene, a chemical used in industry and found in gasoline, can cause leukemia and is linked to non-Hodgkin’s Lymphoma.
A long study from 2000 to 2016 found that using more coal for energy is linked to more cases of lung cancer.
Lung Disease
Air pollution can harm lung growth and cause lung diseases like emphysema, asthma, and chronic obstructive pulmonary disease (COPD). More kids in low-income city areas have asthma, which is linked to outdoor air pollution. A 2023 study found that two pollutants, ozone and PM2.5, cause asthma-related changes in kids’ airways. PM and nitrogen oxide are also linked to chronic bronchitis.
In 2020, the COVID-19 pandemic and wildfires in the western U.S. created a big health problem. A study showed that wildfire smoke made COVID-19 cases and deaths worse. Building on the known link between air pollution and lung infections.
Conclusion
Air pollution harms everyone’s health worldwide. It causes respiratory infections in children and serious diseases. Like Alzheimer’s and cancer in older adults. Studies by organizations like NIEHS show that people living in cities or near busy roads are more likely to get sick from air pollution.
To reduce these health risks, we need to keep studying and working to lower pollution levels. When communities come together and use solutions like better air filters and more green spaces in cities. It helps make people healthier.
Moving forward, it’s crucial to create rules and practices. It make the air cleaner and protect those who are more vulnerable to getting sick. By working together to fight air pollution, we can make the world a healthier place for everyone.