What do the following conditions: low sperm count, menstrual irregularities and premature births have in common? These conditions are a reflection of disruptive changes in our reproductive system. Among the many factors that can cause these changes, an environmental factor which many people may not be aware of is air pollution (AP).
What are the common air pollutants?
Due to human activities and industrialization, our environment has been contaminated with pollutants harmful to our body. The common air pollutants identified so far include the following:
Carbon monoxide: A colorless, odorless gas that is produced by incomplete combustion of petrol or diesel
Sulfur dioxide: A pungent, corrosive gas that is emitted by industrial activities.
Nitrogen oxides: A group of gases formed by high-temperature combustion of petrol in vehicles, power plants, and factories.
Ozone: A byproduct of other pollutants
Particulate matter: Tiny solid or liquid particles that are suspended in the air. They are usually composed of substances such as dust, smoke, soot and chemicals. They can vary in size from less than 2.5 micrometers (PM2.5) to 10 micrometers (PM10) in diameter.
What are the effects of AP on reproduction?
AP can increase the risk of infertility. A study of 18,000 couples in China found that those living with moderately higher levels of small-particle pollution had a 20% greater risk of infertility.
Another study of 600 women attending a US infertility clinic found that increased exposure to air pollution was associated with a lower number of maturing eggs in the ovaries. AR can also impair semen quality by reducing sperm morphology, concentration, motility, and DNA integrity.
Polluted air can cause complications during pregnancy and childbirth. Pregnant mums have increased risks of miscarriage, preterm birth, low birth weight, and stillbirth. AP can also affect the development and health of the fetus and the newborn. These babies are at risk of having chronic diseases such as respiratory and cardiac diseases later in life
How does AP affect reproduction?
Possible mechanisms are as follows:
Air pollutants induce oxidative stress in cells and tissues. As a result, DNA and membranes of the egg and sperm cells may be damaged. Their viability and function will be impaired. Oxidative stress can also affect implantation of the foetus in the uterus and the development of the placenta resulting in miscarriages and premature births.
AP contains substances which are hormone-disrupting chemicals. They interfere with the normal functioning of hormones that regulate reproduction.
AP can cause inflammation in the cells. This can affect the maturation and ovulation of the egg in women, and the production and transport of sperm in men. Inflammation can also trigger immune reactions that can harm the foetus,
The final impact of AP on the individual will also depend on other factors, such as genetic susceptibility, lifestyle habits, nutrition, and exposure to other environmental toxins.
How to reduce AP at home?
The following measures may be helpful:
Adequate ventilation by opening the windows is key to promoting clean air provided our environment is clean.
Quit smoking: one of the most common indoor air pollutants is cigarette smoke.
Use a dehumidifier and/or air conditioner to reduce moisture
Avoid air fresheners, scented candles and incense
Dust surfaces and vacuum frequently
Ensure exhaust fans are functioning in the bathrooms and kitchen
Bathe the pets and wash their bedding often
AP has a significant effect on our health including reproduction. As individuals, we should cooperate in whatever way we can with our government and public health agencies who are working very hard to ensure a clean and healthy environment. Pregnant mums and those planning to conceive should be aware of the air quality and take necessary precautions to minimize exposure to pollutants.