Pesticide Exposure, Agricultural Work Linked to Increased Risk of IPF

Exposure to certain work- and environment-related elements may be the cause of some idiopathic pulmonary fibrosis (IPF) cases, a recent meta-analysis shows. In particular, exposure to pesticides and agricultural work seem to be factors associated with an increased risk of a person developing IPF.

Additionally, exposure to metal dust and wood dust, as well as smoking were associated with a high risk of IPF.

The study, “Occupational and environmental risk factors of idiopathic pulmonary fibrosis: a systematic review and meta-analyses,” was published in Nature Scientific Reports.

Several studies have investigated the possible association between IPF and occupational and environmental exposure factors. “However, the results of such studies are inconsistent,” the researchers wrote.

To learn more, a team of scientists in South Korea conducted an extensive literature search looking for case-control studies that analyzed the effects of work- and environmental-associated risk factors on IPF incidence. Of note, incidence refers to the occurrence of new disease cases in a certain population over a specified period of time.

In total, eight studies were analyzed. These were done in the United States, Japan, Sweden, Southern Europe, Mexico, Egypt, and South Korea, ranging over an 18-year period from 2000 until 2018.

In the selected studies, records from a total of 1,005 IPF patients, with a mean age ranging from 50 to 75, were analyzed and compared with those of 2,497 non-IPF patients of similar ages (control group).

The researchers used statistical analysis to determine the risk of IPF. The results were presented as an odds ratio, or OR, for each factor. Notably, an OR higher than one shows increased odds that an outcome will occur.

Occupational or environmental exposure to pesticides had an OR of 2.07, meaning that patients exposed to pesticides had a 2.07 times higher probability of developing IPF.

“Unlike previous studies, our meta-analysis showed statistically significant increase in IPF risk on pesticide exposure,” the researchers wrote.

Exposure to metal dust, with an OR of 1.83, and to wood dust, with an OR of 1.62, also were found to be associated with an increased risk of IPF.

Farming-related activities or agricultural work had an OR of 1.88, while smoking was associated with an OR of 1.39.

The analysis also indicated jobs that were considered “safer” in the sense that they did not increase, to a high degree, the risk of IPF development. Jobs in the woodworking industry, construction, and textile manufacturing did not appear to pose a significant risk of IPF, according to the analysis.

That is not to say, however, that there was not some increased risk. Instead, according to the researchers, “the risk of IPF increased through working in building, woodworking, and textile industries, but did not reach statistically significant level.”

The scientists also failed to find a significant association between stone, sand, and textile dust exposure and an increased risk of IPF.

“In conclusion, meta-analysis of patient-control studies revealed that exposure to pesticides, metal dust, and wood dust increases the risk of IPF,” as well as an “occupational history of farming or agriculture and ever smoking,” the researchers wrote.

The team pointed out a few limitations to the results, including the fact that the analyzed studies were carried out in specific regions, so they may not be representative of whole countries. In addition, the diagnostic definition of IPF has changed over the years, which could have resulted in diagnostic differences among participants.