David Adair

Hamilton County newborns have some of the worst odds in the country of getting a healthy start in life, with more than one in nine born below what is considered a healthy weight.

The statistic is about more than socioeconomics and gaps in prenatal health care, according to local researchers investigating whether pollution could be partly to blame.

“We can change tobacco use and alcohol use. We can change nutrition. But we think it’s even deeper than that,” said Dr. Carlos Torres, a Chattanooga perinatologist and faculty member at the University of Tennessee College of Medicine, Chattanooga Unit.

Dr. Torres and his colleague, Dr. David Adair, reached out to scientists at UTC to find out why a ZIP code-by-ZIP code analysis shows higher-than-average low birth weight rates across the county regardless of socioeconomic factors.

Sometimes low birth weight can be attributed to premature birth — before 37 weeks of gestation — but Drs. Torres and Adair said they see tiny babies born at full term to seemingly healthy mothers.

The doctors decided to study whether Chattanooga’s unique geography and history as a manufacturing and railroad hub affect the health of local infants.

“Chattanooga is basically like a bowl,” Dr. Torres explained. “We have all these mountains around us, and we have all these foundries. So basically, all these pollutants kind of stay within the city limits, and very nicely reflect all of these ZIP codes.”

A SERIOUS PROBLEM

The nationwide rate of underweight births has reached the highest level in almost 40 years, according to the 2008 Kids Count survey released last month by the Annie E. Casey Foundation, and local rates are among the worst. This worries experts, because low birth weight babies are at increased risk for birth defects, breathing problems, infections, blindness or hearing losses, learning and developmental disabilities and premature death.

The problem is so pronounced nationwide, acting Surgeon General Steven Galson announced recently that developing a national strategy to prevent premature birth is among his top priorities.

Low birth weight has become the No. 1 cause of infant mortality here, according to Jeannette McDonald, infant mortality prevention coordinator for the Chattanooga-Hamilton County Health Department.

Nationally, 8.2 percent of babies born in 2005 weighed 5 pounds 8 ounces or less, the Casey Foundation reports. Tennessee’s low birth weight rate of 9.5 percent puts the Volunteer State in a tie with Delaware and Georgia as 43rd worst in the country.

“When so many babies are born at unhealthy weights, that reveals something about lack of access and education in Georgia,” Gaye Morris Smith, executive director of Georgia Family Connection Partnership, said in a statement last month after the Kids Count report was released.

In Hamilton County the low birth weight rate was 11.1 percent in 2005. That is higher than the rate in some developing nations, according to Ms. McDonald.

From 2001 to 2005, the average low birth weight rate in the county was 11.5 percent, or 2,281 out of 19,807 babies born, according to health department figures.

Dr. Sean Richards, an environmental toxicologist at the University of Tennessee at Chattanooga who has studied low birth weight for the past five years, said researchers are stymied.

“Although we don’t know the cause, we do know that Hamilton County has had an abnormally high incidence of low birth weight over the last 10 to 15 years,” he said.

Within the county, there is significant variation between areas such as Alton Park, in which more than 20 percent of all babies born between 2001 and 2005 were underweight, and Signal Mountain, where the rate was 8.64 percent, according to statistics provided by Ms. McDonald.

Latresea Gustus, of Alton Park, says she can’t help but wonder why her babies have been born smaller and smaller. Ms. Gustus’ first son weighed 8 pounds 101/2 ounces when he was born in 1993; her second, born in 1995, weighed 6 pounds 9 ounces.

Now, six months into her third pregnancy, she has been referred to a high-risk clinic. She said she was told she’s not gaining enough weight, despite the fact that she doesn’t have any chronic health conditions and has been trying to eat nutritiously.

“So far this seems to be my smallest,” Ms. Gustus said.

But low birth weights aren’t just an issue in Alton Park, Dr. Richards emphasized. The rates in Signal Mountain, Lookout Mountain and Hixson, for example, raise a red flag because they surpass the national average, he said.

MORE QUESTIONS

Researchers already have looked at a number of factors known to influence birth weight, including the mother’s health and nutrition, socioeconomic status, education level and access to prenatal care, Dr. Richards said.

But in Hamilton County, “this is an issue across races, and it’s across all socioeconomic boundaries,” he said.

Dr. Adair, a University of Tennessee College of Medicine instructor and nationally recognized perinatologist, is hoping that Dr. Richards and his research team can find out whether environmental factors contribute to underweight babies.

Establishing that kind of a connection may only lead to more questions, but taking steps to determine whether environmental factors can be either included or ruled out is important, Dr. Adair said.

“Certainly, if this is proven, it’s not the sole causative agent,” Dr. Adair said. “It certainly is not going to be earth-shattering in an ‘Erin Brockovich’ kind of way,” he said, referring to the 2000 movie in which a California power company is accused of polluting a city’s water supply.

“But if there is something out there,” he added, “we need to address it and figure out where it’s coming from.”

EXPANDING RESEARCH

Dr. Richards, an associate professor with UTC’s biological and environmental sciences department, has teamed up with Dr. Steven Symes, an associate professor of chemistry at UTC, to find out which substances could be most harmful to birth outcomes here.

To do that, Dr. Richards, Dr. Symes and their research assistant, UTC graduate Justin Conley, are conducting chemical analyses on placentas, the tissue through which mothers deliver nourishment and oxygen to their babies.

Over the past two years, the researchers have collected about 1,000 placentas from mothers at Erlanger hospital, including the placenta of Dr. Richards’ wife following the birth of the couple’s daughter last October.

Dr. Richards hopes to collect at least another 1,000 of the round, dark red slabs to have a large enough sample size to establish a statistically significant trend. He will use placentas from normal weight babies such as his daughter to compare to placentas of underweight babies.

Each mother donating a placenta fills out an anonymous survey in which she can admit to any substance abuse or smoking, provide information about her age, race and medical history and describe the circumstances of her pregnancy.

Researchers will use that data to study trends and will compare the Chattanooga group to a control group of placentas from Knox County to ensure that anything found here isn’t also found in mothers in that area.

Funding for the research came from Dr. Torres’ and Dr. Adair’s practice, Regional Obstetrical Consultants of Chattanooga, along with a $30,000 endowment from UTC’s UC Foundation and another $15,000 to $20,000 from the chemistry department’s Grote Fund.

To continue the project, U.S. Rep Zach Wamp, R-Tenn., has helped them secure a $383,000 federal grant from the U.S. Department of Health and Human Services’ Health Resources and Services Administration.

After sending samples to Southern Illinois University for preliminary testing for polycyclic aromatic hydrocarbons, or PAHs — substances emitted after incomplete combustion that the U.S. Environmental Protection Agency has deemed potentially harmful — Dr. Richards and Dr. Symes decided the most logical place to begin their research was with toxic metals.

Staff Photo by Angela Lewis
Research assistant Justin Conley places placenta samples back after adding nitric acid to them as part of experiments to determine whether toxic metals are present in them in a University of Tennessee at Chattanooga chemistry lab.

Comparing a list of the metals the EPA has highlighted as dangerous in laboratory testing with a list of the substances known to exist in this area, they chose eight metals, including arsenic, cadmium and lead, Dr. Richards said. Some of these metals occur naturally in the soil and others are manmade, he said.

The experiment still is in early stages, Dr. Symes said. Although preliminary indications are that the toxic metals may show up in higher-than-average amounts in underweight babies’ placentas, the overall levels are expected to be relatively low and may turn out not to be enough to have any adverse effect on birth outcomes, he said.

“Right now, we’re taking it one step at a time,” Dr. Symes said. “We try not to have any biases.”

There are too many factors at play to say whether those elements under study definitely affect local birth outcomes, let alone to isolate their exact origin, Dr. Richards said.

“That’s putting the cart way ahead of the horse,” he said. “It would be silly to look for a source at this point because we don’t even know if there is a correlation.”

The mere presence of toxic metals isn’t necessarily enough to cause problems, Dr. Richards explained.

“The body has an amazing defense system,” he said.

For this reason, the team refuses to focus research on any one metal or any one source of pollution in the county.

“If anything,” Dr. Richards said, “we’re trying to rule this out as a factor so we can quit focusing on it.”

NO EASY ANSWERS

The highest rates of underweight births in Hamilton County are clustered in Alton Park and East Chattanooga, areas that historically housed heavy industry, Ms. McDonald said.

However, pinpointing pollution as a cause of low birth weight is difficult because residents in these areas often grapple with poverty and access to health care, she said.

Troy Keith, Chattanooga field office manager for the Tennessee Department of Environment and Conservation’s Division for Remediation, said Chattanooga is no more polluted than any other industrial area in Tennessee. The most state-monitored hazardous sites are in Shelby County, records show, where 22 are slated for investigation and cleanup.

That’s compared to 10 in Knox County and 13 in Hamilton County, according to TDEC records.

In addition, any air quality problems here have been mitigated to comply with EPA standards, said Amber McCorvie, spokeswoman for the Chattanooga-Hamilton County Air Pollution Control Bureau.

But a phenomenon called temperature inversion — which occurs when warmer, less-dense air moves over a cooler, denser air mass to make the air cooler closer to the earth — could mean that toxins blowing in from elsewhere are trapped in all areas of the county, said Shawn O’Neill, a National Weather Service meteorologist in Morristown, Tenn.

“That doesn’t allow the air to rise any further. It rises to that level, and then it just kind of stays to that level and sits there,” Mr. O’Neill said. “The terrain features act like walls, and the inversion acts like a ceiling.”

Still, Dr. Adair said plenty of babies born here are healthy. The research is in such early stages that there is no reason to worry about any serious health risks.

“It is perfectly safe to get pregnant and have babies in Chattanooga,” he said.

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