Logo image
A task-based analysis of black carbon exposure in Iowa farmers during harvest
Journal article   Open access   Peer reviewed

A task-based analysis of black carbon exposure in Iowa farmers during harvest

Emma M Stapleton, Patrick T O'Shaughnessy, Sarah J Locke, Ralph W Altmaier, Jonathan N Hofmann, Laura E Beane Freeman, Peter S Thorne, Rena R Jones and Melissa C Friesen
Journal of occupational and environmental hygiene, Vol.15(4), pp.293-304
04/03/2018
DOI: 10.1080/15459624.2017.1422870
PMCID: PMC6114936
PMID: 29286870
url
https://www.ncbi.nlm.nih.gov/pmc/articles/6114936View
Open Access

Abstract

Diesel exhaust has been associated with adverse human health effects. Farmers are often exposed to diesel exhaust; however, their diesel exposure has not been well characterized. In this descriptive study, we measured black carbon concentrations as a proxy for diesel exhaust exposure in 16 farmers over 20 sampling days during harvest in southeast Iowa. Farmers wore a personal aethalometer which measured real-time black carbon levels throughout the working day, and their activities were recorded by a field researcher. Black carbon concentrations were characterized for each farmer, and by activity, vehicle fuel type, and microenvironment. Overall, 574 discrete tasks were monitored with a median task duration of 5.5 min. Of these tasks, 39% involved the presence of a diesel vehicle. Farmers' daily black carbon geometric mean exposures ranged from 0.1-2.3 µg/m 3 , with a median daily geometric mean of 0.3 µg/m 3 . The highest black carbon concentrations were measured on farmers who used or worked near diesel vehicles (geometric mean ranged from 0.5 µg/m 3 while harvesting to 4.9 µg/m 3 during animal work). Higher geometric means were found for near vs. far proximity to diesel-fueled vehicles and equipment (2.9 vs. 0.3 µg/m 3 ). Indoor, bystander proximity to diesel-operated vehicles resulted in the highest geometric mean black carbon concentrations (18 µg/m 3 ). Use of vehicles with open cabs had higher mean black carbon concentrations than closed cabs (2.1-3.2 vs. 0.4-0.9 µg/m 3 ). In summary, our study provided evidence that farmers were frequently exposed to black carbon associated with diesel-related activities at levels above urban ambient concentrations in their daily work during harvest.
harvest Aethalometer farmers exposure black carbon diesel exhaust

Details

Metrics

Logo image