Air is a basic for life. But we take it for granted. Air pollution is a fact of most modern living now, and crosses boundaries across countries and into neighbourhood — it is difficult avoid it completely.
It can have serious health consequences over a lifetime. It's pretty grim reading, with impacts ranging from strokes to mental health issues.
But clean air is becoming increasingly rare. To the point that in some cities in the world, doing just 30 minutes of exercise does more harm than good [4].
In recent decades, the Environmental Protection Agency (EPA) in the United States has had great success in improving air quality. The emission of air toxins has declined 74 percent since 1990 [5].
However, by 2019, 82 million American’s were still living in counties that pollution levels still exceed the National Ambient Air Quality Standards (NAAQS).
Air Pollution Has Been Well Established as Detrimental to Our Health.
Respiratory and cardiovascular diseases as well as cancer have been linked to air pollution in urban environments [7].Air Pollution Hurts Cognitive Functions.
Air pollution acts as a toxin and promotes inflammatory responses, which may cascade into neuroinflammation, dysregulation and neurodegeneration.
Studies show that air pollution is linked to impaired judgement, mental health problems, poorer performance in school and most worryingly perhaps, higher levels of crime.
Heavy metals in air is one contaminant that crosses the blood-brain barrier. The air we breathe could be changing our behaviour in ways we are only just beginning to understand.
In 2011 that Sefi Roth, a researcher at the London School of Economics was pondering the many effects of air pollution. He was well aware of the negative outcome on health, increased hospital admissions and also mortality. But he was staggered to find a clear link between air quality and how well students perform in their examinations! Read more about his study here.
This can be particularly harmful to children. Researchers at an asthma summer camp found that air pollution was significantly and consistently correlated with acute asthma exacerbations, chest symptoms and lung function decrements [8].A slew of studies have looked at air pollution and students’ academic performance in schools: Mohai et al. 2011; Grineski et al. 2020; Lu et al. 2021; Berman et al. 2018) and absenteeism (Berman et al. 2018; Zhang et al. 2022)
Children Are Especially Vulnerable to Air Pollution
Our young children are most vulnerable to adverse health effects from air pollution due to smaller physiques, faster rates of respiration, and developing organ systems (Legot et al. 2012; Gauderman et al. 2007; Garcia et al. 2021; Calderón-Garcidueñas et al. 2014).
Air Pollution Correlates with Crime and Violence.
Roth analysed two years of crime data from over 600 of London’s electoral wards, and found that more petty crimes occurred on the most polluted days, in both rich and poor areas.
Research, led by Jackson Lu of MIT examined nine years of data and covering almost the entire US in over 9,000 cities. It found that “air pollution predicted six major categories of crime”, including manslaughter, rape, robbery, stealing cars theft and assault. The cities highest in pollution also had the highest crime rates. This was another correlational study, but it accounted for factors like population, employment levels, age and gender – and pollution was still the main predictor of increased crime levels.
Air Pollution Can Result in Reduced Productivity.
This 2016 study backed up the above studies as well as Roth’s initial findings that pollution can result in reduced productivity.
Air Pollution Can Make You Fat.
So we know two people can eat the same foods, and do the same exercise, but over the course of a few years, one may put on more weight… It is due to an impaired metabolism (basically how your body makes energy), and air pollution is one major contributor to worsening metabolism.
Traffic fumes and cigarette smoke are the top culprits because their tiny, irritating particles are able to trigger widespread inflammation and disrupt the body’s ability to burn energy.
“We are starting to understand that the uptake and circulation of air pollution in the body can affect more than just the lungs,” — Hong Chen, a researcher at Public Health Ontario and the Institute of Clinical Evaluative Sciences in Canada.
Particulate Matter (pm2.5) and Nitrogen Dioxide (NO2) - Both of Which Come From Vehicle Exhausts Are Particularly Harmful.
Fine particulate matter (PM2.5) is comprised of solid and liquid aerosolized particles, so these can deposit deep into the lungs causing oxidative stress and inflammation in several organ systems including the cardiovascular, respiratory, renal, metabolic and neurological systems
Check out these studies: Bont et al. 2022; Li et al. 2019; Burkart et al. 2022; Delgado-Saborit et al. 2021.
Researchers couldn’t find any threshold where PM2.5 did no harm, and even those living in the least polluted suburbs of London were affecte.
Very Low Amounts of Carbon Monoxide (Co) Can Impair Brain Functions.
Other air pollutants target the body via separate pathways.
For example, carbon monoxide (CO) binds exceedingly well with Hemoglobin in the body. Hemoglobin, essential for oxygen delivery, binds with CO 200–300 times more than with oxygen, preventing oxygen from binding to hemoglobin (Patel et al. 2023)!
CO is a colorless, odorless, and tasteless gas so carbon monoxide poisoning easily occurs, in which the body experiences severe hypoxia. The symptoms include: a shortness of breath, headache, an altered mental status. Finally, it can lead to death (Patel et al. 2023).
A study of university students exposed to varying levels of CO revealed even low-level exposure resulted in impaired cognition and visual processing (Amitai et al. 1998).
Nitrogen Dioxide Can Cause Respiratory Diseases.
NO2 in air pollution irritates the airways, aggravating including asthma (Epa 2022). It also affect the neurological system, as researchers have found associations between NO2 and dementia (Chang et al. 2014)
more than half of the world’s population now live in urban environments – and more of us are travelling in congested areas than ever before.
References and resources:
Rau AT, Harding AB, Ryan A, Ramirez MR, Renner LM, Berman JD. Ambient air pollution and the risk of violence in primary and secondary school settings: a cross-sectional study. Inj Epidemiol. 2024 Jun 13;11(1):24. doi: 10.1186/s40621-024-00512-6. PMID: 38867329; PMCID: PMC11170797.