11/19/2004

Inhalation and Dermal Exposure among Asphalt Paving Workers

The latest edition of the Annals of Occupational Hygiene contains an article on
"Inhalation and Dermal Exposure among Asphalt Paving Workers".

The primary objective of the study was to identify determinants of inhalation
and dermal exposure to polycyclic aromatic compounds (PACs) among asphalt
paving workers. The study population included three groups of highway
construction workers: 20 asphalt paving workers, as well as 12 millers and 6
roadside construction workers who did not work with hot-mix asphalt.

During multiple consecutive work shifts, personal air samples were collected
from each worker's breathing zone. All exposure samples were analyzed for PACs,
pyrene and benzo[a]pyrene. Inhalation and dermal PAC exposures were highest
among asphalt paving workers. Among paving workers, inhalation and dermal PAC
exposures varied significantly by task, crew, recycled asphalt product (RAP)
and work rate (inhalation only). Asphalt mix containing high RAP was associated
with a 5-fold increase in inhalation PAC exposures and a 2-fold increase in
dermal PAC exposure, compared with low RAP mix.

The inhalation PAC exposures were consistent with the workers' proximity to the
primary source of asphalt fume (paver operators > screedmen > rakers > roller
operators), such that the adjusted mean exposures among paver operators were 12
times higher than among roller operators. The dermal PAC exposures were
consistent with the degree to which the workers have actual contact with
asphalt-contaminated surfaces (rakers > screedmen > paver operators > roller
operators), such that the adjusted mean exposures among rakers were
approximately 6 times higher than among roller operators.

Paving task, RAP content and crew were also found to be significant
determinants of inhalation and dermal exposure to pyrene. The effect of RAP
content, as well as the fact that exposures were higher among paving workers
than among millers and roadside construction workers, suggests that the PAC and
pyrene exposures experienced by these paving workers were asphalt-related.

Further Information


AplusA-online.de - Source: Annals of Occupational Hygiene