Occupational exposure to diesel engine exhaust: A literature review

Abstract

Diesel exhaust (DE) is classified as a probable human carcinogen. Aims were to describe the major occupational uses of diesel engines and give an overview of personal DE exposure levels and determinants of exposure as reported in the published literature. Measurements representative of personal DE exposure were abstracted from the literature for the following agents: elemental carbon (EC), particulate matter (PM), carbon monoxide (CO), nitrogen oxide (NO), and nitrogen dioxide (NO 2 ). Information on determinants of exposure was abstracted. In total, 3528 EC, 4166 PM, 581 CO, 322 NO, and 1404 NO 2 measurements were abstracted. From the 10,001 measurements, 32% represented exposure from on-road vehicles and 68% from offroad vehicles (30% mining, 15% railroad, and 22% others). Highest levels were reported for enclosed underground work sites in which heavy equipment is used: mining, mine maintenance, and construction (EC: 27-658 mg/m 3 ). Intermediate exposure levels were generally reported for above-ground (semi-) enclosed areas in which smaller equipment was run: mechanics in a shop, emergency workers in fire stations, distribution workers at a dock, and workers loading/unloading inside a ferry (generally: ECo50 mg/m 3 ). Lowest levels were reported for enclosed areas separated from the source, such as drivers and train crew, or outside, such as surface mining, parking attendants, vehicle testers, utility service workers, surface construction and airline ground personnel (ECo25 mg/m 3 ). The other agents showed a similar pattern. Determinants of exposure reported for enclosed situations were ventilation and exhaust after treatment devices. Reported DE exposure levels were highest for underground mining and construction, intermediate for working in above-ground (semi-) enclosed areas and lowest for working outside or separated from the source. The presented data can be used as a basis for assessing occupational exposure in population-based epidemiological studies and guide future exposure assessment efforts for industrial hygiene and epidemiological studies.

Oxidative Stress, Inflammatory Biomarkers, and Toxicity in Mouse Lung and Liver after Inhalation Exposure to 100% Biodiesel or Petroleum Diesel Emissions

“…Occupational studies showed that there may be a greater incidence of cough, phlegm, and chronic bronchitis among those exposed to diesel CE than among those not exposed (Pronk et al, 2009). Reductions in pulmonary function have also been reported following occupational exposures in chronic studies (Rudell et al, 1996).…”

“…This was because of the following two reasons: (1) Several studies reported increased acute respiratory symptoms, chronic bronchitis, and aggravation of asthma upon exposure to PM (Pronk et al, 2009;Rudell et al, 1996), and (2) of the six mouse strains tested, BALB/cJ mice were reported to be the best inbred strain that closely mimics the phenotype of human occupational asthma (De Vooght et al, 2010).…”

“…The effects of BD and BD blends on regulated and non-regulated emissions were studied and compared with those of for various on-and off-road dieselpowered applications (Boehman et al, 2005;McCormick 2005; Bugarski et al, 2006;Williams et al, 2006). Data indicate that the composition and concentration of the emissions depend on several factors, including operating conditions, type of engine, fuel composition, and additives used (Obert, 1973;Ullman, 1989), which in turn influence the amount of exposure in different occupations (Groves and Cain, 2000;Pronk et al, 2009). In general, the BD and its blends were found to reduce emissions of nonvolatile fractions (Boehman et al, 2005;McCormick, 2005; Bugarski et al, 2006) and to elevate particle-bound semivolatile organic fractions of BD exhaust particles (McDonald et al, 1995;McCormick, 2005;Purcell et al, 1996).…”

Assessment of Workplace Diesel Exhaust Exposure and Health Effects

“…A recent review by Pronk et al [5] reported literature on occupational uses of diesel engines and subsequent personal exposure to diesel exhausts. Over 10,000 assessments of elemental carbon, particulate matter, carbon monoxide and nitric oxides measurements were included; with 32% on road exposures; 68% off road exposures (including 30% mining and 15% rail).…”

“…Hazardous levels of diesel exhaust can be found in occupations ranging from mining to driving diesel-fuelled trucks or forklifts [5]. Durability and fuel efficiency have lead to an increase in the use of diesel engines.…”