Adequacy of Benzo(A)Pyrene and Benzene Soluble Materials as Indicators of Exposure to Polycyclic Aromatic Hydrocarbons in a Söderberg Aluminum Smelter

Abstract

Occupational and environmental exposure to polycyclic aromatic hydrocarbons (PAHs) occurs as a complex mixture that is evaluated using specific components, such as benzo(a)pyrene (BaP) and benzene soluble materials (BSM). Factors that influence the relationship between BaP, BSM, and other PAHs within an aluminum smelter were investigated. Personal samples collected from 1978 to 2001 were used: 576 samples were analyzed for both BaP and BSM; 479 samples were analyzed for BaP and nine other particulate PAHs. Differences in the log-transformed ratios (PAH/BaP, BaP/BSM) due to anode paste composition, pot group, season, and job were examined using linear regression. Pot groups represented differences in technology, process conditions, and building properties. The models' predicted PAH/BaP ratios were multiplied by BaP relative potency factors to estimate the relative toxicity of the mixture. The correlation between BaP and BSM depended on the anode paste source (range 0.1-0.8). In linear regression, 27% of the variability in the log-transformed BaP/BSM ratio was explained by coal tar pitch, work area, and job; no seasonal or pot group differences were observed. Within the potrooms, BaP was very strongly correlated with other PAHs (majority > 0.9). Depending on the PAH, between 23% and 89% of the variability in the log-transformed PAH/BSM was explained by season, coal tar pitch, pot group, and job. The BaP toxic equivalency factors of the mixture varied more across job (2.1-3.5) than across coal tar pitch source (1.8-2.8) or pot group (2.3-2.5). Seasonal and work area differences in the relationship between BaP and other PAHs have not been reported previously. Until these relationships are better understood, BaP seems to be a reasonable, albeit imperfect, indicator due to the strong correlation between BaP and other PAHs for a given set of conditions and due to the relative abundance of BaP exposure measurements.

Structure of flavonoids influences the degree inhibition of Benzo(a)pyrene – induced DNA damage and micronuclei in HepG2 cells

“…These compounds are formed from natural and man-made INHIBITION OF GENOTOXICITY OF BENZO(A)PYRENE BY FLAVONOIDS sources, but the man-made B(a)P is quantitatively the most significant [9]. B(a)P has been implicated in the evolution of various cancers of lung and colon; people are exposed to B(a)P through cigarette smoking [10], occupational exposure [11], and intake of broiled or smoked food [12]. B(a)P has been shown to induce gene mutations, chromosomal aberrations and other types of genotoxic effects both in vitro and in vivo [13].…”

Bladder cancer and the aluminium industry: a review

“…Given the variable PAH composition and the difficulty in accurately assessing PAH exposure in an industrial environment, it has been difficult to characterize the precise PAHs responsible for carcinogenesis. Furthermore, it is thought that specific PAH distributions can vary with different smelting technologies, anode paste composition, work‐shifts and jobs [15,16]. All of these factors have made the characterization and quantification of PAH exposure extremely difficult in industrial workers.…”

“…All of these factors have made the characterization and quantification of PAH exposure extremely difficult in industrial workers. Benzene‐soluble materials (BSM) and benzo(a)pyrene (BaP) are the two most commonly used measures of exposure to PAH in industrial studies [15]. Friesen et al.…”

“…Friesen et al. [15] investigated factors that influence the relationship between BaP, BSM and other PAHs in a vertical‐stud Soderberg aluminium smelter in Canada. These authors found the BaP most strongly correlated with other PAHs, and recommended its use as a marker for PAH exposure.…”

Relationship between cardiopulmonary mortality and cancer risk and quantitative exposure to polycyclic aromatic hydrocarbons, fluorides, and dust in two prebake aluminum smelters

“…In addition to lung and bladder cancer, exposures in Söderberg smelters have also been associated with nonHodgkin lymphoma and pancreatic, stomach and kidney cancers [9][10][11][12][13][14], and with other chronic diseases, including fluoride exposure with respiratory disease mortality [12,15] and CTPV exposure with chronic obstructive pulmonary disease mortality [13,14] and heart disease mortality [16,17]. However, these findings have not been consistent across studies.…”