There are good studies, bad studies... and then this

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Despite ACSH's efforts to promote sound scientific practices in public health research and journalism, there are always some researchers who seem to manipulate data and stretch them to limits unjustified by any rational interpretation. And, what's more, ostensible science journalists continue to publicize these non-studies as more important than they are.

In one such case, Reuters Health reported on new research on asthma risk factors, headlining the story "Workplace pollutants tied to kids' asthma risks." This study, presented at the annual congress of the European Respiratory Society, claims to have found evidence that a pregnant mother's exposure to pollutants in the air while at work may lead to a higher probability that her child will develop asthma.

Yet when one considers the basis of this study's conclusions, the relationship is far less clear. After reviewing data on over 45,000 seven-year-old children and their mothers, the Danish researchers estimated the mothers' exposure to workplace pollutants during pregnancy based only on the mothers job titles at the time. In addition, the difference they found in asthma risk for children was small: 18.6 percent among kids whose mothers were believed to have been exposed to higher pollution levels, versus 16.1 percent in the general population. Considering the enormous variety of factors that may be involved in a child's risk of asthma, along with the dubious method of estimating pollutant exposure, there is little to be gleaned from this report in the way of concrete conclusions.

ACSH's Dr. Gilbert Ross criticizes the alacrity with which Reuters reported the conclusion despite the lack of any real evidence. This is all noise. There is no signal here the only signal is the headline, he notes. They estimated the exposure to pollutants based on job titles, then claimed that this is the first study showing a link between workplace pollutants and children's asthma seven years later.