Summary
This study compares two populations of rural dutch residents in areas with high or low density of concentrated animal feeding operations (CAFOs) and their incidence of conditions like respiratory diseases and gastrointestinal conditions. They found an increase of pneumonia, atopic eczema and “other infectious diseases” (which the authors use as a stand-in for Q-fever) in residents living near CAFOs. The risk for pneumonia and “other infectious diseases” was especially elevated by goat CAFOs. Other conditions were not increased. Among the strengths of this study are usage of data from general practitioners to mitigate errors through patients having to recall their conditions later. Another strength is the investigation of both individual and group-level factors. A limitation of this study is the limited information about possible other factors that could be different in the two populations, like air pollution or health behavior, which could affect the association between CAFOs and the investigated health conditions. Additionally, the authors did not control for false positive results that could come from the multiple statistical tests for diseases (i.e., the authors did not account for multiple statistical comparisons). In conclusion the authors state that they found positive associations between goat CAFOs and pneumonia and other infectious diseases.
There is growing interest in health risks of residents living near concentrated animal feeding operations (CAFOs). Previous research mostly focused on swine CAFOs and self-reported respiratory conditions. The aim was to study the association between the presence of swine, poultry, cattle and goat CAFOs and health of Dutch neighbouring residents using electronic medical records from general practitioners (GPs).
Data for the year 2009 were collected of 119,036 inhabitants of a rural region with a high density of CAFOs using information from GIAB (high exposed population). A comparison was made with GP data from 78,060 inhabitants of rural areas with low densities of CAFOs (low exposed population). Associations between the number of CAFOs near residents’ homes and morbidity were determined by multilevel (cross-classified) logistic regression.
In 2009, the prevalence of most respiratory and gastrointestinal conditions was similar in the high and low exposed population. Exceptions were pneumonia, atopic eczema and unspecified infectious diseases with an increased prevalence, and sinusitis with a decreased prevalence in the high exposed population. Within the high CAFO density region, the number of poultry, cattle and swine CAFOs near residents’ homes was not associated with allergic, respiratory or gastrointestinal conditions. Conversely, each additional goat CAFO within the postal code area of residents’ homes significantly increased the odds of unspecified infectious disease and pneumonia by 87 and 41 percent, respectively.
Using GP records, pneumonia and unspecified infectious diseases were positively associated with the number of goat CAFOs near residents’ homes, but no association was found between swine, cattle, and poultry CAFOs and respiratory, allergic or gastrointestinal conditions.