Article Text
Statistics from Altmetric.com
Dummer and colleagues, research provides an important step towards establishing the evidence base around the adverse pregnancy outcomes associated with incinerators and crematoriums.1 Investigating the possible adverse health effects from environmental hazards is a public health challenge that demands the use of systematic and reproducible research methods. We have some concerns regarding the study described by Dummer and colleagues.
The study focuses on selected “fatal” pregnancy outcomes. One key concern is that this excludes miscarriages, abortions, and non-lethal congenital anomalies. Excluding these outcomes may misrepresent and underestimate any possible association between the exposures under consideration and “pregnancy outcomes”. Indeed, it is possible that the “fatal” pregnancy outcomes considered by the researchers may actually be inappropriate in relation to the chemicals released from incinerators and crematoriums. Studies on exposure to lead, for example, indicate that the most likely pregnancy related outcomes associated with high exposure are low birth weight, spontaneous abortion, and length of gestation.2
The measurement of exposure in this study is also unclear. The reason for this is that distance from an incinerator or crematorium is used as a surrogate measure of exposure and the pathway for the absorption of “toxic pollutants” is considered to be direct inhalation of pollutants or contact through food, soil or water contamination.
Actual pollution levels at the sites are not provided and there is no indication of whether these sites are located in isolation or located in close proximity to other industrial processes. Under these circumstances is difficult to see how the surrogate measure of distance could be used as a proxy for exposure to emissions from incinerators and crematoriums.
We question the robustness of any study conducted over such a long period. The margins of error, based around outcomes …