Assessing Pollution’s Effects on Infant Development

June 2013Diana Austin

Household air pollution (HAP) from cooking fires is a killer, causing 3.5 million deaths worldwide in 2010, including 300,000 deaths among children under 1 year of age, according to a study published in December 2012 in The Lancet.

UCSF School of Nursing faculty member Lisa Thompson knows these dangers well. As a co-investigator on the landmark RESPIRE (Randomized Exposure Study of Pollution Indoors and Respiratory Effects) study, she examined the links between exposure to HAP and acute respiratory infections in rural Guatemalan children.

She observed that infants born to mothers who had received a plancha – a special woodstove with improved ventilation – during the prenatal period had higher birthweights than those whose mothers used traditional open-fire stoves. To build on that research, Thompson, who has spent a decade investigating the effects of air pollution on babies and young children, is conducting a pilot study to test methods to examine the effects of HAP on infants’ and young children’s neurodevelopment.

“The study builds on the infrastructure that’s been there for 10 years, so we have the same location, we have the same people working for us, and we’re enrolling participants in the same communities,” says Thompson. Titled NACER (Newborns and Children Exposed to Respiratory Pollutants), after the Spanish word for “to be born,” the study is following 36 pregnant women and their infants from 16 weeks’ gestation through one year after birth, measuring both pre- and postnatal exposure to pollutants and assessing infants’ growth and neurodevelopment.

Looking at New Tools to Assess Development and Measure Exposure

As part of the study, Thompson is using a new comprehensive assessment procedure that specially trained fieldworkers can use to make a rapid assessment of infant neurodevelopment. Pediatric neurologist Naila Zaman Khan, head of the Department of Pediatric Neuroscience at Dhaka Shishu (Children’s) Hospital and academic director of Bangladesh Institute of Child Health, developed the instrument – which doesn’t require assessors to have special expertise in child development – for use in low-resource settings.

Lisa Thompson “I read about it in an article in Pediatrics and thought it was a simple tool I could use in Guatemala,” says Thompson. In June 2012, she went to Bangladesh to be trained and certified in its use.

The following month, she and Kate StormoGipson and Rebecca Kooistra, two students in the UCSF Family Nurse Practitioner Program, went to Guatemala to train two health workers to administer the assessment and to see how it worked in a rural Guatemalan setting.

“We had to adapt it so that families in our study area would accept what we were doing with the newborns,” says Thompson. “For example, Guatemala is much colder than Bangladesh, so mothers don’t like their babies to be unwrapped. We had to use space heaters and do the exams with clothed infants.” Thompson and her team validated the results against a “gold standard” neurodevelopmental assessment tool.

In addition to assessing neurodevelopment, NACER investigators are using personal monitors attached to the mothers to measure pollution exposure directly. “It’s really one of the first studies to do this [as opposed to relying on self-reporting], and to intensively look at the neonatal period and infant neurodevelopmental outcomes and see if there is any link with air pollution,” says Thompson.

Building on NACER for Future Studies

Although NACER is a small pilot study, it’s already bearing fruit in the form of collaboration with other researchers investigating methods for assessing pollution exposure and its effects on health. Thompson, for example, is serving as co-investigator on a study looking at air pollution and pregnancy outcomes that will be conducted by one of her colleagues on RESPIRE, John McCracken (of the Universidad del Valle de Guatemala), in hospitals and community clinics in Quetzaltenango, the second-largest city in Guatemala.

In addition, she is working with researchers at the University of Pittsburgh and UC Berkeley to look at particulate matter samples captured in filters – and with researchers at UCSF’s Clinical Pharmacology Lab and Duke University environmental toxicologist Joel Meyer to study urine samples from the Guatemalan women for pollution-associated carcinogens and signs of oxidative stress.

“The hope is that we can find more efficient methods of measuring exposure to air pollution, such as urinary biomarkers,” says Thompson.

NACER will wrap up in December 2013, and Thompson hopes it will pave the way for a larger longitudinal study that would isolate the effects of air pollution exposure in utero and during the first two years of life from other factors that can affect neurocognitive development, such as malnutrition or lack of access to education. She also hopes to do a randomized stove intervention, as they did in RESPIRE, this time looking at both neonatal outcomes and neurodevelopment.

Living in the Smoking Section

Recently, Thompson highlighted the enormous health burden posed by HAP to Melinda Gates, co-chair of the Bill & Melinda Gates Foundation, when Thompson and several other UCSF faculty members were invited to meet with her this April.

During her visit to UCSF, Gates received the UCSF Medal, the university’s highest honor, given to individuals who have made outstanding contributions to health worldwide. Thompson hopes that increased awareness of HAP’s significance will result in more research into its causes and help identify effective interventions.

“Thousands of studies have shown that smoking causes lung disease and low birthweight,” she says. “To borrow an analogy from my former advisor at UC Berkeley, Kirk Smith, you can divide the world into those who smoke and those who don’t smoke. Currently, 40 percent of the world’s population is living in the smoking section, and something needs to be done to change this.”