Cleaning chemicals linked to asthma in young children

Sarah Boseley, health editor
Thursday August 26 2004
The Guardian

Fumes given off by cleaning products and solvents in the home may be a cause of asthma in young children, according to new research.

Australian researchers measured the levels of chemicals, called volatile organic compounds (VOCs), in the homes of children under three with asthma. These VOCs are given off by commonly used cleaning products, polishes and air fresheners as well as paints, floor adhesives, fitted carpets and cigarette smoke.

Their study, published today in the journal Thorax, says that although the number of children in the study was relatively small - 88 toddlers with asthma and 104 without - it showed a marked increase in asthma risk among those children with higher levels of VOCs in their homes. Yet the levels measured were below the levels generally recommended as acceptable indoors.

Krassi Rumche, of the school of public health at Curtin University of Technology in Perth, Australia, and colleagues, who conducted the study, say some of these VOCs are carcinogenic as well as having a possible association with asthma.

"There is insufficient evidence concerning the health implications of VOCs at concentrations commonly found inside houses," they write. "Research in this area is complicated by the wide range of relevant VOCs and the continual appearance of new products which release different combinations of these compounds."

They studied children aged six months to three years who had been admitted with asthma symptoms to the accident and emergency department of the Princess Margaret hospital in Perth and compared them with a second group of children without asthma recruited from very similar backgrounds.

Two weeks after the emergency hospital visit in the winter and again in the summer, the researchers took measurements in the children's homes to establish the levels of VOCs. The parents also completed questionnaires on the children's health and the children were subjected to a test for allergies.

More children were allergic (77%) among those with asthma than among those without (50%), as would be expected, but the significant finding was that levels of indoor pollutants were higher in the homes of children with asthma. The highest risk was for the chemical benzene, followed by ethylbenzene and toluene. For every 10 unit increase in toluene and benzene, the risk of asthma increased by almost two times and three times, respectively.

A second study in the journal from a different group of Australian researchers suggests that children exposed to fumes from indoor heaters in the first year of life could be 47% more likely than others to develop wheezing and hyperactive airways (rapid narrowing) which are features of asthma.

Gas appliances, in particular, emit higher levels of nitrogen dioxide than would be found outdoors, say the authors, Guy Marks from the Woolcock Institute of Medical Research at the University of Sydney and colleagues. Some epidemiological studies have linked nitrogen dioxide with an increased risk of respiratory symptoms and illnesses.

The authors of the study say that if their findings are backed by further researches, the type of heaters used in homes with babies should be reviewed.

Source: The Guardian