Passive exposure to bleach at home is linked to higher rates of childhood respiratory and other infections, according to a new study.

During the study, published in the journal Occupational & Environmental Medicine, researchers looked at more than 9,000 children, aged 6 to 12, living in the Netherlands, Finland and Spain. In order to find out the potential impact of exposure to bleach in the home, their parents were asked to complete a questionnaire on the number and frequency of flu, tonsillitis, sinusitis, bronchitis, otitis, and pneumonia infections their children had in the year prior to the study.

While bleach use was commonly used in Spanish schools (72 percent), it was rare in Finland, only used 7 percent of the time.

The researchers found that the number and frequency of infections were higher among children whose parents regularly used bleach to clean the home in all three countries. For example, the risk of one episode of flu in the previous year was 20 percent higher, and recurrent tonsillitis 35 percent higher, among children whose parents used bleach to clean the home compared to those who did not.

Likewise, the risk of any recurrent infection was 18 percent higher among children whose parents regularly used cleaning bleach.

The high frequency of use of disinfecting cleaning products, caused by the erroneous belief, reinforced by advertising, that our homes should be free of microbes, makes the modest effects reported in our study of public health concern," the research team said in a press release.

So what is it about passive exposure to bleach that seems to lead to these childhood infections? The researchers suggest that the volatile or airborne compounds generated during the cleaning process are irritating and may damage the lining of lung cells. This, in turn, causes inflammation and makes it easier for infections to take hold. Bleach may also potentially suppress the immune system, they added.

Though this is simply an observational study and does not establish a cause-and-effect relationship, it does shed light on the possible harmful effects of bleach use in the home and warrants further research.

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