Polluted in the Womb
By Theresa Chung, Health Science, 2023
In recent centuries, the burning of fossil fuels has dramatically increased the amount of pollutants in the air. Coal, one of the most used fossil fuels in the world, is very toxic. It releases dangerous compounds, including carbon monoxide molecules, particulate matter (or soot), mercury, and more. In areas where fossil fuels are being burned regularly, the population is forced to continually breathe in these substances. This can lead to severe damage to humans’ respiratory systems, nervous systems, and cardiovascular systems. In addition to affecting the directly exposed population, even those who have not yet been born are being affected by pollution — a mother can actually present a danger to her baby still in the womb, as the pollutants inside her body can reach the fetus itself.
Even those who have not yet been born are being affected by pollution.
A 2019 study done by researchers at Hasselt University in Belgium found that samples of placenta after birth showed accumulations of black carbon (BC) particles on the side that faces the fetus. These BC particles arise from the emission of burning fossils fuels, such as gasoline, diesel, and coal, and remain in the environment as air pollutants. The study found that in women who had less exposure to air pollution, there was an average particle count of 9,500 BC particles in the placenta. For women who were highly exposed, there was an average count of 20,900 BC particles present. The researchers concluded that higher amounts of air pollution correlated with higher amounts of BC present in the placenta.
The universal understanding of the placenta’s purpose is that it is a temporary organ that serves as a barrier between the fetus and the mother during pregnancy, in order to protect the fetus from any harmful things present in the mother’s body. However, it turns out that the placenta is not impenetrable enough to prevent the permeation of pollutants. Previous research has shown that pollutants such as alcohol and therapeutics have crossed through the placenta and made it to the fetus. Thus, there is little reason to doubt the idea that pollutant particles such as BC could not make it past the placenta and cause severe damage to the fetus.
It turns out that the placenta is not impenetrable enough to prevent the permeation of pollutants.
The study found that these BC particles have already accumulated on the placenta during the early stages of pregnancy. The fetus undergoes development in a stage known as the “critical window,” during which the fetus is most likely to be affected by environmental exposure. Prior research done in 2007, 2011, and 2013 by Beate Ritz, Carole B. Rudra, and Dr. Marie Pedersen in the United States and the European Union has shown that particulate matter that has reached the fetus during the critical period is “associated with lower birth weight, preterm birth, and intrauterine growth restriction.” Fetuses exposed to pollutant particles, including BC, are often born prematurely, or are smaller than they should be because they were not able to grow fully in the womb.
Particulate matter that has reached the fetus during the critical period is “associated with lower birth weight, preterm birth, and intrauterine growth restriction.”
As we continue to use fossil fuels that release toxins into the air we breathe, the amount of people who start off their lives already subject to the harmful effects of pollution will continue to increase. Particulate matter present in air pollutants can easily be breathed in and kept in the body for as long as pollution remains an issue. As more and more fossil fuels are being burned everyday, studies are more frequently coming out to show that humans are suffering due to the pollutants present wherever they go. Breathing in polluted air is causing asthma in some, while others are suffering from lung cancer due to the carcinogens present in these pollutants. If we continue to burn fossil fuels at this rate, we can expect that most people will have already have accumulated so many toxins inside our bodies that it will be rare for us to not be plagued by a pollution-related health issue early in life.
DOI: 10.1038/s41467–019–11654–3