To live in the 21st century is to live in a toxic world. Rapid urbanization and the increased burning of fossil fuels over the past century has made people more susceptible than ever to harmful chemicals in the air, soil, and water including carbon dioxide, volatile organic compounds, and endocrine disrupting chemicals.
These pollutants increase the risk of many chronic illnesses such as cancer, heart disease, and lung disease, making it a significant global health problem.
Conditions linked to everyday chemicals—used in cosmetics, plastics and common household items like sofas—lead to $340 billion in treatment and lost productivity costs annually in the U.S. (R).
Controlled studies show that when you pump in volatile organic compounds and carbon dioxide in the air to levels that are within the range of normal and found in office environments (the worst 25% of offices), many important parameters of cognition go down dramatically.
The magnitude of effects from breathing cleaner air is greater than any nootropic you may be taking. Cognitive scores were 101% better when there were lower volatile organic compounds and carbon dioxide levels.
Read more to learn about the detrimental effects of pollution and environmental toxins on human health.
What is Environmental Pollution?
Following the industrial revolution, increased urbanization and economic development have led to a surge in energy consumption and waste emissions (R).
Because of this, environmental pollution is reaching troubling proportions worldwide. According to a recent World Health Organization (WHO) report, 92 percent of the world’s population are living in polluted regions that exceed WHO safety limits (R).
Children in these areas are especially at risk. A recent UNICEF report (October 2016) found that nearly 600,000 children under age five are dying annually from diseases caused or exacerbated by outdoor and indoor air pollution, particularly in lower-income countries (R).
The alarming rise in environmental toxins is considered a major public health problem, costing the United States nearly 340 billion dollars in annual health care expenditures (R).
Among the most concerning of these pollutants are carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), volatile organic compounds (VOCs), ozone (O3), heavy metals, and respirable particulate matter, all of which have been linked to prenatal defects, respiratory disorders, heart disease, mental disorders, as well as increased likelihood of disease and reduced life expectancy (R,R2).
Many of these chemicals originate from man-made sources including transportation sources (e.g., vehicles) stationary sources (e.g., factories, power plants, and refineries), and indoor sources (e.g., building, cleaning, and cooking materials) (R,R2).
Bad Health Effects of Pollution
1) Pollution Increases the Risk of Cancer
Particulate Matter (PM), a major component of outdoor air pollution, is classified as a group 1 carcinogen by the International Agency for Research on Cancer (IARC), meaning that there is enough evidence to conclude that it causes cancer in humans (R).
Cancer rates are skyrocketing in villages across China (where levels of air pollution are among the highest observed worldwide), a phenomenon credited to rising levels of atmospheric particulate matter from exhaust, coal smoke and vehicle fumes in these regions (R).
The International Agency for Research on Cancer also found that long-term air pollution exposure is a direct cause of lung cancer. Lung tissue is particularly susceptible because of its extensive contact with inhaled airborne carcinogens (R).
Volatile organic compounds are organic compounds that can become volatile (gaseous) at room temperatures. They are found at higher levels indoors due to their emission by many common household products and office materials (e.g., paints, carpets, air fresheners, disinfectants, and pesticides) (R,R2,R3).
A number of volatile organic compounds are suspected or known to cause cancer, including benzene, formaldehyde, vinyl chloride, carbon tetrachloride, 1,2-dichloroethane, trichloroethylene, and chloroform. Chronic exposures have been linked to the development of leukemia, lymphoma, myeloma and angiosarcoma in humans (R,R2,R3,R4).
In the World Health Organization (WHO) Global Burden of Disease project, it was estimated that urban air pollution worldwide (as measured by concentrations of PM) contributes to about 5% of all deaths from tracheal, bronchial, and lung cancers (R).
The main evidence confirming the carcinogenicity of air pollution comes from human and animal biomolecular studies revealing its association with DNA damage, inflammation, oxidative stress, altered telomere length and impaired DNA methylation (R).
2) Pollution Depresses Immunity and Promotes Autoimmune Disorders
Although genetic factors are implicated in autoimmune disease, the incidence of autoimmunity is rising too rapidly to conclude that only population-level genetic changes are responsible, indicating that environmental factors are largely involved (R).
Indeed, many people with environmental illnesses have an array of autoimmune diseases which are linked to air pollution (R).
Organic solvent exposure is a risk factor for autoimmune disease and has been associated with the development of systemic sclerosis, primary systemic vasculitis, and multiple sclerosis in humans (R).
3) Pollution Triggers Allergy/Asthma and Impairs Lung Function
Epidemiological studies indicate that air pollution is correlated with an increased frequency of respiratory allergy, especially in people living in urban areas compared to rural populations (R).
Subsets of particulate matter smaller than a certain size (≤0.1 μm) known as PM0.1, are particularly dangerous. These particulates can penetrate the deepest (alveolar) portions of the lung and enter the blood circulation, causing direct damage to a variety of different organ tissues (R).
Children growing up in heavily polluted areas (with high O3, PM, and aldehyde levels) exhibit irregular structural changes in the nasal lining. These defects can lead to impaired airway clearance, lung infection and inflammation (R).
High levels of ozone are associated with extensive airway and lung tissue damage as well as more severe asthma symptoms and increased respiratory hospital admissions/deaths in Europe and the US (R, R2).
Other components of traffic-related pollution such as sulfur oxides, nitrogen oxides, and carbon monoxide have been linked to the development of respiratory complications including lung congestion, fluid build-up in lung tissues, wheezing, and lung infections (R,R2,R3,R4).
4) Pollution Damages the Brain and Accelerates Cognitive Decline
In a study of middle-aged and older adults, it was found that a minimal (2 µg) increase in PM was associated with a higher risk of brain stroke and smaller brain volume, both biomarkers of brain aging (R).
Carbon dioxide and volatile organic compounds, both commonly found in new buildings, are believed to be related to sick building syndrome, a condition characterized by headaches, memory problems, drowsiness, and mental confusion/brain fog.
A controlled trial found that the cognitive performance (i.e., crisis response, strategy, and information usage) of office workers who worked in conditions with low carbon dioxide and volatile organic compound levels were nearly double that of those who worked in conventional office environments (with high volatile organic compounds and carbon dioxide), indicating that these chemicals can diminish intellectual capacity (R, R2).
Despite the increased use of unleaded gasoline, lead still remains an outdoor air pollutant in many parts of the world. Prenatal exposures have been shown to alter brain function and lower IQ levels in children (R).
Inhaling other heavy metals can cause neurobehavioral impairments (R).
For example, mercury, an element released from coal-burning power plants, is toxic to neurons and can lead to a neurological disorder characterized by irritability, difficulty concentrating, cognitive impairment and memory loss (erethism) (R).
High-level exposures to manganese can also cause neurological defects. One study found that Mn concentration (in blood, urine, and toenail samples) was inversely correlated with overall neurocognitive performance (assessed by memory, concentration, and motor tests) in welders and smelters (R).
5) Pollution Can Cause Depression and Other Mood Disorders
Studies in neuronal cell cultures have shown that diesel exhaust particles can activate microglia and induce the death of dopaminergic neurons (by increasing inflammation and reactive oxygen species (ROS)). Because dopamine depletion in the central nervous system (CNS) is known to be involved in the development of depression, air pollution may trigger or exacerbate depressive symptoms by inducing dopaminergic neurotoxicity (R,R2).
Data from human observational studies support a positive correlation between air pollution (e.g., CO, NO2, O3, PM) and frequency of depressive disorders, suicide attempts, and even migraine and headache symptoms (R,R2,R3).
Organic solvents (e.g., toluene, xylene, benzene, and trichloroethylene) have been reported to cause a number of psychological/mood disturbances including anxiety, depression, and panic attacks in exposed individuals (R).
6) Pollution May Increase the Risk of Heart Disease
A growing body of epidemiological and clinical evidence establish a consistent link between outdoor air pollution and the incidence of heart disease and stroke (R).
The most concerning of these air-borne pollutants include carbon monoxide, nitrogen oxide, sulfur dioxide, ozone, lead, and particulate matter. These toxins are associated with high rates of hospitalization and death due to heart disease, especially in patients with congestive heart failure and arrhythmia (abnormal heart rhythms) (R).
This is likely due to the promotion of vascular dysfunction, inflammation, oxidative stress, blood clot formation, and increased blood pressure by pollutants, all of which are risk factors for heart disease/failure (R).
7) Pollution Increases Insulin Resistance and May Cause Type 2 Diabetes
High concentrations of particulate matter (PM2.5) were found to impair energy metabolism and glucose homeostasis, as well as increase inflammation in insulin-responsive organs in an animal model of type 2 diabetes (R).
Chronic exposures to air pollution can also worsen the clinical outcomes of diabetic patients. One study showed that pollutant exposure enhanced the vulnerability of diabetic patients to heart disease and stroke risk factors (R).
8) Pollution Causes Wrinkles and Premature Skin Aging
Airborne particle exposure is strongly correlated to skin aging signs, particularly pigment spots and wrinkles (R).
It is proposed that the damages stem from the ability of many pollutants to pass through the skin and activate inflammatory pathways, stimulate melanin production from melanocytes (causing unwanted sunspots) and trigger new blood vessel growth (causing redness and Rosacea) (R).
Skin damage resulting from pollutant exposure also activates repair processes that remove collagen, resulting in wrinkles (R).
9) Pollution Impedes Reproductive Function and Fertility
There is an alarming rise in spontaneous abortions among wildlife species across the U.S. which scientists are attributing to environmental pollutant exposure (R).
Similarly, a marked reduction in live birth rates and increased risk of miscarriage was observed in women (undergoing in vitro fertilization) exposed to high concentrations of nitrogen dioxide and particulate matter(R,R2).
A number of these pollutants are hormonal disruptors and can interfere with the action of hormones that control growth, development, and fertility (R).
Studies have shown that these chemicals tamper with estrogen, androgen, and progesterone receptors, leading to a myriad of reproductive anomalies in humans and animals ( i.e., preterm birth, miscarriage, birth defects, low sperm count, and prostate cancer) (R).
Air pollution also has a negative impact on semen quality. A study in men found that high-level air pollution exposure was significantly associated with defects in a number of semen measures including fewer motile sperm, more abnormally shaped sperm and more sperm chromosomal aberrations (R).
10) Pollution Interferes with Thyroid Activity
Extracts of outdoor and indoor airborne particulate matter significantly inhibit thyroxine (T4) binding to transthyretin, a carrier protein that transports T4 throughout the body. Transthyretin binding inhibition can lead to blood thyroid hormone depletion, which disrupts thyroid homeostasis and potentially increases the risk of thyroid cancer (R,R2).
It is thought that pollutants from car emissions and organic solvents can trigger autoimmune thyroid diseases by interfering with iodine transportation and inducing oxidative stress, thereby initiating an inflammatory response to the thyroid gland (R).
Some pollutants act as hormonal disruptors (e.g., PCBs, BPAs, and Phthalates) and block thyroid hormone binding to its receptor.
11) Pollution May Increase the Risk of Obesity
Elevated levels of traffic-related pollution are associated with a higher body mass index in children (R).
It is proposed that air pollutants trigger inflammatory pathways that promote diabetes and fat storage. This theory is supported by animal studies showing that mice exposed to air pollution and fed a fat chow diet developed more body fat and insulin resistance than mice who ate the same diet but breathed clean air (R).
12) Pollution May Weaken Bones and Discolor Teeth
A population-based cohort study in Taiwan found that carbon monoxide and nitrogen dioxide exposure was associated with an increased risk of osteoporosis in men and women (R).
Air pollution exposure induces systemic and tissue-specific inflammation, which may decrease bone mineral density by stimulating osteoclastic (bone loss) activity. This idea is further supported by studies revealing bone mineral density loss in patients with chronic inflammatory diseases (R,R2).
Fluorine, an element commonly used in many industrial processes, can build up in bones (during chronic high-level exposures) and cause hypermineralization (hardening of bone), resulting in reduced joint mobility, abnormal bone formation, and an increased risk of bone fracture (R,R2,R3).
Long-term exposures can also lead to dental fluorosis, a condition manifested by white, yellow, brown, and black stains on tooth enamel (R).
13) Pollution May Expedite the Aging Process
Telomere length, a hallmark of biological aging, is shortened in subjects exposed to traffic pollution (R).
Progressive telomeric shortening leads to cellular aging, death or cancer transformation, thereby elevating the risk of many chronic conditions including cancer and heart disease (R).
14) Pollution May Cause Kidney Disease
Because the kidneys receive roughly 25% of the resting cardiac output (despite making up only about 0.5% of total body mass), large amounts of chemicals and drugs in the body circulation are delivered to the kidneys (R,R2).
Also, as kidneys form concentrated urine, they accumulate toxic pollutants in the tubular fluid. Thus, a pollutant present at nontoxic levels in the blood can reach toxic levels in the kidney, increasing the likelihood of tissue injury (R).
One study in China found higher rates of membranous nephropathy, an immune disorder that can lead to kidney failure, in regions with elevated levels of fine PM (R).
15) Pollution Damages the Liver
Air pollutants such as diesel exhaust particles, particulate matter, coal fly ash, and carbon black have been shown to induce liver toxicity and worsen liver inflammation and fat build-up in several animal models, indicating that they may trigger or exacerbate liver diseases in humans (R).
16) Pollution is Detrimental For Gut Health
Evidence from animal models suggests that chronic gut exposure to high levels of particulate matter could lead to the development of GI inflammatory diseases by increasing gut permeability, decreasing colonic motility, and altering gut microbiota composition and function (R,R2).
17) Pollution May Lead to Eye Damage
Residents living in heavily polluted areas are at higher risk of developing dry eye syndrome (R).
Age-related cataracts are a leading cause of blindness worldwide. Smoking, a major source of indoor pollution, is strongly linked to cataract formation, likely due to the presence of Cadmium and Lead in cigarette smoke (R).
Solutions to Reduce the Negative Effects of Pollution
1) Minimize Exposure
The primary way to avert the health risks of pollution is by taking action to reduce personal exposure. Below are some individual-level strategies based on current evidence:
- Purifying indoor air: Air cleaning systems can reduce indoor pollutant levels of outdoor/indoor origin. You need to make sure to get systems that can purify VOCs and gases, such as the Air Oasis. I have air purifiers in the house running.
- Staying indoors (assuming you have purifier): Environmental protection agencies in many countries advise people to stay indoors during days where are high amounts of air pollution. However, some outdoor pollutants such as PM, ozone, and other gasses can infiltrate indoors, with infiltration rates varying due to differences in building structures and operating conditions. Levels of indoor air pollutants of outdoor origin are mainly determined by the means of outdoor-to-indoor transport, which is dependent on air exchange rate. Closing windows can effectively reduce air exchange rate (up to 50%) and thereby reduce outdoor pollutant infiltration. Since VOCs, mold and other contaminants build up indoors, you need an effective air purifier.
- Avoiding outdoor activity when levels are high: Avoiding rigorous, extended outdoor activity during high air pollution days and/or near high-traffic roadways and sources of combustion (e.g., wood burning) reduces pollutant inhalation exposure.
- Quitting Smoking: Environmental tobacco smoke (ETS) or secondhand smoke is a major source of indoor air pollution and a significant contributor to indoor PM and VOC levels.
- Opting for Safer Consumer Products: Many commercial products are key sources of indoor air pollutants including VOCs, and endocrine disrupting compounds (EDCs) (e.g., pesticides; polybrominated diphenyl ethers (PBDEs), flame retardants polychlorinated biphenyls (PCBs), alkylphenols, surfactants, and parabens). Reading labels and choosing products that are mainly plant-based, paraben-free, fragrance-free, and that do not contain ethanolamines organochlorines, antimicrobials (e.g. triclosan), alkylphenol-based surfactants (i.e. nonionic surfactants), dichlorobenzene, phthalates, methylene chloride, toluene, and carbon tetrachloride can limit indoor exposure to these chemicals
2) Natural Interventions
Many studies have highlighted the impact of select micronutrients in mitigating the harmful effects of air pollution. Research shows that:
- NRF2 supplements
- Airway hyperresponsiveness induced by NO2 in healthy subjects is completely prevented with Vitamin C pretreatment
- Vitamin C, Vitamin E, and β-carotene protect against the short-term effects of high ozone exposure on lung functions and alleviate nasal inflammation
- Broccoli/broccoli sprouts rich in glucoraphanin may reduce the harmful impact of PM pollution on allergic disease and asthma
- Polyunsaturated fatty acids (PUFAs) and vitamin E can reduce lung inflammation and oxidative stress induced by PM2.5
- Vitamin C and E supplementation can reduce fat/protein/ DNA damage by boosting antioxidant defenses
- PUFAs and B vitamins can improve heart function and prevent Heart Rate Variability (HRV) decline induced by PM2.5