The Importance of a Clean Water Supply: Lead Contamination in Water Affects Birth Rates

You may know that lead contamination is a particular concern for parents and pediatricians around the globe, because exposure to lead, while horrible for adults, has even graver consequences for children, and for pregnant women. The World Health Organization (WHO) considers no level of lead safe, because this heavy metal accumulates in body tissues of multiple organ systems, is distributed through brain, liver, bones, and kidneys. In bones and teeth, lead is actually stored for long periods of time. There, it accumulates, but it also leaks out from bone during pregnancy, so can enter and affect the fetus.

Once in the brain, it is known that lead retards brain development. It may have other negative effects too. In fact, recently scientists at West Virginia University Department of Economics and the University of Kansas examined birth rates in Flint, Michigan in the aftermath of the city’s recent water contamination tragedy, and the results are startling. The contamination begin in the spring of 2014, when the city switched its water supply to the Flint River and the water was not treated properly, but no warning was issued until nearly two years later. However, since the rest of Michigan did not switch water supplies, the non-Flint population of Michigan, including those similar economically to Flint, could be used as a control group, a factor that enabled the recent study.

During the time that Flint’s water supply was exposing its residents to high levels of lead,  275 fewer children were born compared with other periods when the water was more pure. Flint’s fertility rates plummeted compared with Michigan’s other large urban center in association with the contaminated water.

In the course of the study, researchers too records of births and fetal death during the years of the contamination, and compared them between different Michigan cities. The results suggest that fertility rates decreased 12 percent for women in Flint. There also was a 58 percent increase in fetal death, while the general health of Flint children declined during the two years that the water supply was contaminated. It’s not clear whether the drop in birth rate is due to a drop in fertility among women or men in Flint, or simply to an increase in the number of miscarriages. It’s certainly possible, however, that it could be a combination of effects. However, the study also found a dramatic increase in concern about the Flint water supply, indicated trends in Google searches. Thus, the researchers think that it’s possible that the drop in birth could be due, at least part, to the people of Flint worrying to the point that people decided to hold off on having children.

As a water source, the Flint River has a long history connected with pollution. After using the river as source for over a century, the city stopped drawing from it in 1967, because of pollution from the automobile industry.

Lead comes from the Earth’s crust, which is to say that it is naturally occurring. It is an environmental problem, because it has numerous uses. Activities such as manufacturing, smelting, mining, lead paint, recycling, lead in aviation fuel and, in some countries still in automobile fuel all contribute lead to the environment that we inhabit. Lead acid batteries account for more than 75 percent of lead in use throughout the planet. Additionally, lead is used in stained glass, certain crystal glassware, solder, ceramics, ammunition, some cosmetics, and even some toys.

The brains of young children are particularly vulnerable to lead toxicity. Along with the apparent effect on birthrates, lead at high levels also is associated with stillbirths, miscarriages, premature birth. Exposure of pregnant women to high levels of lead can cause miscarriage, stillbirth, premature birth and low birth weight.

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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