Addressing Children's Environmental Health Concerns in the Yakima Valley

Dr. Catherine Karr, a member of the Center for Ecogenetics and Environmental Health (CEEH) and Director of the Northwest Pediatric Environmental Health Specialty Unit (PEHSU) spoke November 10th at the Environmental Protection Agency's Children's Health Month brownbag webinar in Seattle. Her topic was Addressing Children’s Environmental Health Concerns in the Yakima Valley.

Dr. Karr and her team work with community groups to understand environmental exposures and health effects on children in the Yakima Valley. Their research studies, part of El Proyecto Bienestar (The Well-Being Project), include indoor and outdoor air pollution and childhood asthma, pesticide exposure, and nitrate-contaminated drinking water from wells. Their goal is to make conditions better for the community.

The Yakima Valley is an agricultural area. 50% of the population is Hispanic and an additional 6% belong to the Yakama Nation. Health disparities are widespread. Compared to all US children, children in the Yakima Valley experience higher than average rates of poverty, obesity, premature birth, asthma hospitalizations, and adverse childhood events. Children in the Yakima Valley are found to have organophosphate pesticide metabolites in their urine, substances that are associated with neurological issues such as Attention Deficit Hyperactivity Disorder (ADHD). The Yakima Valley is also home to a birth defect cluster of anencephaly and spina bifida that is 4-times the expected occurrence. The cause has not been determined.

Dr. Karr's research begins with the community who, through El Proyecto Bienesta, identified their priorities for environmental health research. The first topic the community wanted to investigate was why so many kids have asthma. This is important new research as most air pollution studies have looked at pollution from city traffic. 

58 children with asthma enrolled in the Aggravating Factors of Asthma in a Rural Environment (AFARE) study. The kids were followed for 2 years. Their lung capacity (FEV1) was measured daily, the community health worker called each family every 2 weeks to assess control of asthma symptoms, and participants' lung function was tested once a year by health providers. To assess air pollution, daily measures of small particulate matter (PM 2.5), fine dust that gets deep into the lungs, were taken in the community, and ammonia monitors were placed at some kids' homes.

Haze from air pollution
The number of days with PM 2.5 levels above federal standards was found to be more days than in Seattle. In the winter, 5% of days had PM 2.5 above federal standards. High PM 2.5 is caused by winter inversions, woodsmoke, agricultural burning, and ammonia, from animal feeding operations (AFOS).

Karr reports that initial findings show evidence of more asthma symptoms and worse lung function the day after high air pollution days. Only 26% of the children had consistently “well-controlled” asthma, based on symptoms and medication use. But over the course of the study, all of the children improved. Karr attributes this to frequent monitoring and follow-up by the community health worker.

The study suggests that community air pollution contributes to asthma morbidity, and that efforts to reduce air pollution from AFOS and PM 2.5 may reduce asthma morbidity and benefit children. 

Even as Karr prepares to publish the AFARE study findings, she and her team are embarking on a follow-up study. Thanks to a new $2.5 million grant from the National Institute of Environmental Health Sciences, they will conduct an interventional study to evaluate the effectiveness of high-efficiency particulate air and ammonia (HEPA/NH3) purifiers in the homes of a new group of children with uncontrolled asthma. The 5-year study is called HAPI: Home Air in Agriculture Pediatric Intervention Study. Enrollment is now underway. 

Responding to a question from listeners, Dr. Karr said her personal recommendation for an air filter is a HEPA filter with a pre-filter for odor (ammonia). She suggested not using an ionizing filter as it would contribute to harmful ozone in the home.

CEEH provided pilot funding for a component of the AFARE study. Others involved in Dr. Karr's research in the Yakima Valley include CEEH researchers Chris Simpson, Edmund Seto, and Mike Yost, researchers in the Pacific Northwest Agricultural Safety and Health Center (PNASH), Heritage University, Yakima Valley Farm Workers Clinic, and the Northwest Community Action Center, which includes Radio KDNA.

Read more about Dr. Karr's research in this February 2015 article in HS Newbeat.

-- Marilyn Hair