(dailyRx News) Phthalates are substances used to make plastic more flexible. They are contained in a number of items from personal care products like shampoo to flooring, electrical cords and toys.
Children can be exposed to high levels of phthalates because they spend a lot of time on the floor and put plastic toys in their mouths. New research suggests that high levels of phthalate exposure might increase a child's risk for asthma.
Researchers in Norway studied 623 10-year-olds to look at the relationship between phthalate levels in the children's bodies and rates of asthma and allergies.
Results showed that the children with the highest levels of certain types of phthalates had the highest asthma rates.
Randi J. Bertelsen, PhD, of the National Institutes of Health, Department of Health and Human Services in North Carolina, and colleagues wanted to find out if there was a link between phthalate levels in children and whether or not they had developed asthma or allergies by age 10.
For their study, researchers analyzed data from 623 10-year old children from a larger study. The large study was called the Environment and Childhood Asthma (ECA) study and it was conducted in Oslo, Norway.
The ECA study looked at lung function among healthy babies born in 1992 and followed their health for two years. After 10 years, the researchers conducted a follow-up with the children.
The 10-year follow-up for each of the children was done between September 2001 and December 2004. Caretakers were interviewed about their children’s health history, including allergies and asthma symptoms or diagnosis.
Blood samples were taken and skin prick tests were done to test for allergies in the children. Researchers also tested the children’s lung function, making them breath into a machine that measured their lung capacity.
Urine samples were also collected from the children. The samples were tested for the presence of different types of phthalates.
All of the children with asthma had had asthma symptoms and/or used asthma medication in the past year.
The results of the study showed a link between asthma in children and the highest exposure to the kind of phthalates used as plasticizers in PVC items like flooring, car interiors and toys.
Children with the highest levels of one type of phthalate - called mono(carboxyoctyl) phthalate - in their blood system had about 1.9 times the odds of having asthma compared to those exposed to lowest levels.
Children with the highest levels of a different type - called mono(carboxynonyl) phthalate - had about 2.2 times higher odds of having asthma.
The researchers did not find a link between asthma and the other types of phthalates they tested for. Similarly, they found no relationship between phthalate exposure and the development of allergies.
The study was published on November 15, 2012 in the journal Environmental Health Perspectives.
The research was funded by the Norwegian Institute of Public Health, Research Council of Norway and Oslo University Hospital, as well as the Intramural Research Program of the National Institutes of Health (NIH), National Institute of Environmental Health Sciences (NIEHS).
Partial funding was also provided by pharmaceutical company AstraZeneca Norway. However, the authors declared that the sponsor had no influence on the analysis, interpretation or presentation of the study.
The authors reported no potential conflicts of interest.