Occupational exposure of goat farm workers to particulate matter and endotoxin

Intensive livestock farming exposes workers to elevated levels of particulate matter (PM) and endotoxins, increasing respiratory health risks. Although personal exposure has occasionally been investigated in the 3 major livestock sectors-cattle, pigs, and poultry-emerging sectors such as intensive goat farming remain understudied. This study aimed to quantify personal exposure to inhalable dust, PM10, and endotoxins among workers on Dutch dairy goat farms and to explore associations between exposure levels, specific work tasks, and farm characteristics.

Repeated personal air sampling was conducted among 41 participants working at 15 goat farms. Inhalable dust and PM10 samples were collected using filter-based methods attached to portable air pumps. For all inhalable dust and PM10 samples, PM mass concentrations were determined by gravimetrical analyses and endotoxin concentrations with the Limulus-Amebocyte-Lysate assay. Determinants of exposure levels were analyzed by linear mixed modeling.

Inhalable dust concentrations showed a median of 0.966 mg/m3 (range: 0.228 to 3.093), with a median endotoxin concentration of 612 EU/m3 (range: 48 to 7,818). For the PM10 concentrations, a median of 0.376 mg/m3 (range: 0.070 to 1.233) was observed, with a median endotoxin concentration of 700 EU/m3 (range: 8 to 2,886). In total, 90% of the samples exceeded recommended occupational exposure limits for endotoxin (>90 EU/m3). PM10 and inhalable dust concentrations were strongly correlated (Pearson r = 0.71), as were endotoxin concentrations in both fractions (Pearson r = 0.71). Exposure to PM and endotoxin varied significantly between farms, within farms and within workers. Overall, highest exposures were recorded for workers with milking as a primary job task.

Goat farm workers are exposed to substantial levels of PM and endotoxins during routine work activities. On average, concentrations exceeded those reported for dairy cattle farm workers, yet remained lower than levels typically observed in pig and poultry farming. The observed considerable variation in exposure both between farms and among individual workers necessitates future research and more detailed microbiological characterization of air samples on determinants of exposure, to guide appropriate measures in husbandry and practices at goat farms. This research highlights that in emerging intensive livestock farming sectors, increased exposure to PM and endotoxins-and related health effects-can be expected among workers unless reduction of these exposures is explicitly addressed in the development of agricultural policies and practices.