The National Children’s Study (NCS) recently chose the University of California, Davis, (UC Davis) as one of 22 national sites to recruit 1,000 women who are pregnant or about to become pregnant and to study their children’s development from infancy through childhood and adolescence. The final birth cohort of 100,000 children will form the largest U.S. study to date of children’s health. Dr. Irva Hertz-Picciotto will lead the new Center at Davis, which will bring nearly $32 million to UC Davis for health research over the next seven years.
Hertz-Picciotto’s award includes two NCS research sites in Northern California— Sacramento County and San Mateo County. Her team plans to compete for a third site in Humboldt County. Hertz-Picciotto says the new cohort will be a “national treasure” for the study of early exposures and their effects on childhood health including obesity, diabetes, asthma, injuries, autism, other neuro-developmental disorders, and mental health. “These conditions are of high concern because of the lifetime costs and morbidity, and in some cases early mortality. Several of these disorders are increasing. Childhood obesity and Type 2 diabetes in children were almost unheard of 30 to 40 years ago. Autism and asthma are on the rise. We don’t yet know all of the causes or all of the solutions. That is our goal.”
Hertz-Picciotto credits her colleagues at UC Davis with a stellar application for the new sites. Dr. Richard Sweet, who heads a Center for Women’s Health and will serve as Co-Principal Investigator, and Dr. Richard Pan, a pediatrician with strong ties to the community, are two among an impressive roster of health researchers who played an important role in the application. Other assets were the team’s collaboration with UC Davis’s Clinical and Translational Science Center led by Dr. Lars Berglund—one of 12 across the country funded by the National Institutes of Health to translate basic science into clinical practice—and the involvement of UC Davis’s Center for Children’s Environmental Health with its expertise in cutting-edge autism research.
Certain that UC Davis researchers can influence the NCS research agenda, Hertz-Picciotto highlights environmental sampling, retention of study subjects, and early screening of autism (before 36 months) as key areas of focus. She says, “Richard Pan will develop a team of site coaches from the community who will work with the study team, not on data collection, but to stay in touch with mothers to keep the families engaged.” The coach will address issues such as transportation and childcare to increase retention.
Hertz-Picciotto says her vision is to learn enough from the study to reduce the incidence of each high priority health condition by 10% to 20%. Even if the study results reduce each of them by one percent, she says the study will pay for itself because diabetes, autism, or obesity that starts early in life exerts a huge cost on society, the medical system, and those who suffer with the condition.
Novel Findings in Childhood Respiratory Illness
Hertz-Piciotto’s recent article in the leading journal Environmental Health Perspectives underscores how her research and study methods connect to those of the National Children’s Study.
The research team examined the link between the respiratory health of 1,133 children from birth to 4.5 years and their exposure to ambient air pollution in two Czech Republic districts, Teplice and Practhatice. The former district, a coal mining town, was known for poor air quality. In contrast, Practhatice had light industry and low levels of ambient air pollution. After adjusting for season, temperature, and other covariates, her results showed that during the first two years of life, exposures over a 30 day average period to ambient polycyclic aromatic hydrocarbon (PAH) and fine particles (PM2.5) were associated with a 30% increase in the risk of bronchitis. In older children aged 2 to 4.5 years, the risk increased to 56% for PAH and 23% for PM2.5.
This study may be the first to use long-term data on PAH exposures with daily measurements over all winter months. PAHs—found outdoors from diesel exhaust and coal plant combustion and indoors from tobacco smoke and wood stoves—are more expensive to measure than PM2.5. Hertz-Picciotto notes, “PAHs occur on particles but they also occur in a gaseous phase. We are hypothesizing that the effect may not be just local in the lung where the particles lodge and disrupt cell function, but PAHs are being absorbed into the bloodstream and may be having an impact more generally on the immune system and its ability to mount an appropriate response.”
These results are notable because of the size of the cohort and the 95% retention rate. In the Czech Republic, with its open public health infrastructure, each child is registered with a pediatrician. The participation rate among pediatricians was 100%. Nurses and pediatricians extracted the study data from medical records—a more accurate data collection method than self-reported questionnaires.
The team collected data on lower respiratory illness, including bronchitis, bronchiolitis, and croup. A further category included these illnesses plus obstructive pulmonary disease, pneumonia, or asthma. While many studies have focused on asthma and hypersensitivity, Hertz-Picciotto says, ”bronchitis is actually more common than asthma. And though it is something from which you recover more quickly, it is a source of much morbidity with a strong public health impact. It also means lost work days for parents.”
Hertz-Picciotto met her Czech collaborators through the International Society for Environmental Epidemiology (ISEE) of which she is a founding member and served as President from 2000-2002. She also served as President of the Society for Epidemiologic Research and on the editorial boards of Epidemiology, American Journal of Epidemiology, and Environmental Health Perspectives. She received her Ph.D. in Epidemiology from the University of California, Berkeley, School of Public Health.