Curmudgeon’s Corner

Our Debt to Richard Nixon: Low Birth Weight and Air Pollution

By Jacob Schor, ND

We owe a debt to Richard Nixon. Few people remember him in a favorable light. We remember him for sabotaging the Vietnam peace talks, the whole Watergate thing, and of course the business about being a crook or not. We forget that he established the EPA.

It was Richard Nixon who signed the executive order that created the Environmental Protection Agency (EPA) back in 1970. The first legislation put forward by the EPA was the Clean Air Act, which passed into law in 1972. What we now call the clean water act began as the Federal Water Pollution Act first of 1948 but was rewritten in 1972 as the Federal Water Pollution Control Act during Nixon’s tenure. We can’t give him credit for its passage. He vetoed the bill on October 17, 1972, but the House and the Senate overrode this veto the very next day and the Clean Water Act became law without his aid.

Thus, one should probably give Nixon credit for passing at least some of the legislation that has had the most lasting impact on environmental quality in US history. It’s weird to think about, I know.

Airborne particulates and or air pollution are blamed for a long list of health problems. Nitrous oxide levels are linked with suicide rates.¹ Fine particulates appear to increase anxiety levels in women² and worsen diabetes.^3,4 Urban air pollution increases mortality rates; what we should call the bottom line in health.⁵

Given the EPA’s current lack of enforcement of existing regulations, outdoor air quality may deteriorate in the near future. We can still influence our indoor air quality to a great extent by simply using air filters. Even short-term utilization of a HEPA air filter has significant impact on biomarkers of illness, for example, lowering c-reactive protein levels significantly in days.⁶

The current theory to explain why these tiny particles have such a profound impact on health suggests that once inhaled they actually translocate across the membranes of the lungs, enter the circulation and deposit at various sites in the body; in particular they accumulate where there is preexisting inflammation, triggering further inflammatory reaction.⁷ They make bad things worse.

Over the past few months there have been a number of papers published that link air pollution, particularly superfine particulates, to risk of low birth weight infants.

In early December the British Medical Journal published an article that examined the impact of air and noise pollution on birth weights of infants in London.⁸ Rachel Smith and colleagues conducted a retrospective population-based cohort study to examine the relation between exposure to air and noise pollution from road traffic and whether there was an effect on birth weight. Their study included all live births in the greater London area occurring between 2006 and 2010. They used official birth registries and identified 671,509 births. Some of these births were excluded because the moms lived too close to the area boundary, had premature births at less than 24 weeks, the infants had implausible birth weights, or missing gestational ages. In the end, the researchers still had 540,365 births for analysis.

Modern software allowed the researchers to pinpoint the location of homes where the moms lived to almost inches. Pollution and noise levels were calculated to 20-meter grids across the city. Low birth weight (LBW) was defined as less than 2500 grams (~88 ounces) and a gestational age of 37 weeks.

Air pollution from road traffic in London was clearly not good for babies. The authors estimated that 3% of the low birth weight births in London are directly caused by exposure during pregnancy to fine particulate matter (PM2.5) levels greater than 13.8 μg/ m³.

The study did find a link between traffic noise and birth weight. For each interquartile increase in air pollution exposure however there was a 2-6% increase in the odds of a LBW delivery.

We want very much to prevent babies coming out small. That is because underweight babies are more likely to have bad things happen; they are born too early, suffer from worse fetal distress, are delivered by C-section more often, have lower Apgar scores, end up with hypoglycemia, are in the hospital more often, and are more likely to die.⁹ Low birth weight girls are more likely to end up with preeclampsia themselves when they become pregnant years later.¹⁰ Very low birth weight is associated with brain structure abnormalities and cognitive impairment.¹¹ Preterm birth leads to hyper-reactive cognitive control processing and poor white matter organization in adulthood.¹²

Low birth weight is also a predictor of person’s future health.^13,14 A low birth weight is associated with high low-density lipoprotein and total cholesterol levels in men, and hypertension and diabetes mellitus in women as they age.¹⁵

This study on its own should make us worry about the health risks of air pollution. Yet there is more to it; this paper by Smith et al is just one of a series of recent studies that came to similar conclusions. As I write this during the second week of December 2017, Smith et al is one of four significant studies already published this month.

Also published in December is a study by Kingsley et al that examined ambient air pollution and preterm births in Rhode Island. The air is relatively clean in Rhode Island, yet Kingsley’s group reported that increased PM2.5 exposure was still associated with a 12-16 grams lower birth weight (n=61,640). Kingsley’s group estimated that for every 2.5 µg/m³ increase in PM2.5 exposure during pregnancy, risk of preterm birth increased 4%.¹⁶

Liu et al examined maternal exposures to particular matter in Shanghai, China, and reported, also in December, more dramatic effects than the Rhode Island researchers, probably because pollution in Shanghai is far worse. In Shanghai where the annual average PM2.5 concentration was 56.19μg/m³, the study estimated that 33% of preterm births and 23% of low birth weight births were directly caused by pollution.¹⁷

In yet another December publication, Ng et al report analysis of data on births in California (N=1,050,330). Interquartile increases in exposure to total PM2.5 were associated with a 7.7% increased risk of LBW births.¹⁸

As mentioned these studies were published in just the first two weeks of December. My haphazard search going back through last summer finds similar reports from across the world including Jinan, China,¹⁹ Scotland,²⁰ Connecticut,²¹ and Cape Cod, Massachusetts.²² These research results are consistent enough for us to pay attention. Air pollution exposure during pregnancy is very likely to increase risk of a LBW birth. This is a problem.

This brings to mind an article Walter Crinnion, ND, wrote on air pollution back in 2015. Dr. Crinnion is well known for teaching courses on environmental medicine through a group called SpiritMed.

Much more focus needs to be placed on recognizing the important role that common air pollutants hold in health, with commensurate actions being taken to reduce the levels of common air pollutants in the home—the one environment most people are in control of. It is quite possible that one of the most effective preventive medicine modalities would be the installation of a high-quality air purifier in the home.²³

This conclusion is even truer today; it is doubly true for women during pregnancy. Using an air filter may be the most effective single thing a person can do to improve their health. Based on these recent studies I guess we should amend this to read, “Using an air filter may be the most effective single thing a person can do to improve their health and that of their babies.”