Let's set the record straight on what is "conclusive evidence."
Hundreds of studies have been published confirming air pollution as a threat to the viability of a pregnancy and to the healthy development of the human embryo. Air pollution triggers the same harmful inflammatory cascade, and disease outcomes, as you would expect from diluted cigarette smoke. That's no surprise because chemically it is very similar. All organs can be affected, including what most people might consider their favorite ones — heart, lungs, brain and, in the case of a pregnant mother, the placenta and fetus.
At least two biological pathways put the fetus at risk. The aforementioned inflammation releases chemical mediators that narrow the body's network of tiny blood vessels, including those that comprise the placenta. Studies in both animals and humans have proven that air pollution does in fact cause narrowing and increased tortuosity of placental vessels, hindering normal blood flow. It takes little imagination to appreciate that compromised blood flow to the baby can jeopardize normal development.
A second pathway is particulate pollution itself. Once inhaled and distributed throughout the blood, tiny pollution particles, and the harmful chemicals and metals attached to them, can penetrate any cell in the body. They can, and do, cross the placenta, enter the fetus, infiltrate the nucleus of cells where the chromosomes are, and irreversibly interfere with the exquisitely delicate and critical process of organ development, especially the brain.
Having been exposed throughout intrauterine life to the same chemicals, and millions of the same particles that the mother inhales, babies are now born "pre-polluted." One study found that the average umbilical cord contained 287 different chemicals and heavy metals. Of those, 134 were known to cause cancer, 151 caused birth defects, 154 were endocrine disrupters and 158 were neurotoxins (many chemicals have more than one effect).
Clinical studies are equally disturbing. Virtually every type of pregnancy complication is known to occur at higher rates in pregnant mothers exposed to more air pollution — miscarriages, still births, birth defects, premature births, low birth weight syndrome, hypertension, pre-eclampsia, premature rupture of membranes and even gestational diabetes.
After birth, the pollution threat to babies continues, triggering higher rates of respiratory related infant mortality and SIDS. Even brief air pollution exposure during critical developmental windows provokes chromosomal damage of several different types, "programming" the fetus to a wide range of chronic diseases decades later, including diseases of the heart, lungs, nervous system, and cancer.
Air pollution shortens placental telomeres (the "end caps" of chromosomes). Placental telomeres are highly predictive of a newborn's life expectancy. There is wide variability in the length of newborns' telomeres, most of which is related to environmental exposures, not genetic predisposition. Bottom line: maternal exposure to air pollution programs her baby to a shorter life span.
In lab animals, air pollution causes actual anatomic changes in the fetal and neonatal brain. A new study now documents that in humans. Just likes videos have changed the national conversation on tolerance for police shootings, recent MRI scans of damaged children's brains should change the conversation about our tolerance for air pollution.
Science, logic, compassion and moral obligation are united in compelling us that what we have accepted in the past is no longer acceptable. The harm to ourselves is too great, the harm to the weak and vulnerable is even greater, and the harm to future generations can be irreversible. Utah Physicians for a Healthy Environment will be telling a more detailed version of this story in Vernal, Friday (April 17) at 7 p.m. at Vernal Junior High. We encourage the public and UDOH to attend.
Brian Moench, M.D., is president of Physicians for a Healthy Utah.