Evaluation of exposure to polycyclic aromatic hydrocarbons in a coke production and a graphite electrode manufacturing plant: assessment of urinary excretion of 1-hydroxypyrene as a biological indicator of exposure.

Abstract

Objectives-Characterisation of the airborne concentration of 13 polycyclic aromatic hydrocarbons (PAHs) at various workplaces in a graphite electrode and a coke production plant. Validation of the urinary excretion of 1-hydroxypyrene (hydroxypyrene) as a biological marker of exposure to PAH.Design-Cross sectional study of workers exposed to PAHs (106 in the graphite electrode producing plant and 16 in the coke works).Methods-Personal air sampling during at least six hours per workshift using a glass fibre filter and a Chromosorb 102 solid sorbent tube and analysis of PAHs by high performance liquid chromatography (HPLC) and spectrofluorometric detection (SFD). Collection of spot urine samples before and after the shift and analysis of 1-hydroxypyrene by HPLC and SFD.Results-The workers most exposed to PAHs were those occupied at the topside area of the coke oven plant and those working in the blending and impregnation areas of the graphite electrode producing plant (mean airborne concentration of total PAHs: 199 and 223 pg/m' respectively). Except for naphthalene and perylene, the relative proportion of the different PAHs did not differ between the plants. Pyrene concentration in air was highly correlated with the total airborne PAH concentration (r = 0-83, p < 0-0001) and the correlation coefficients between hydroxypyrene concentration in postshift urine samples and pyrene or total PAHs in air were 0-67 (p < 00001) and 0-72 (p < 00001) respectively. Excretion of hydroxypyrene doubled when the exposure to pyrene in air increased 10-fold. The half life for the urinary excretion of hydroxypyrene was around 18 hours (95% confidence interval 16-1-19-8). Smoking habits only explained 2-3% of the variance in hydroxypyrene excretion compared with 45% for the pyrene concentration in air.Conclusion-The determination of the urinary excretion of hydroxypyrene in postshift urine samples can be used as a suitable biomarker to assess individual exposure to PAHs in coke ovens and in graphite electrode manufacturing plants.

Excretion Profiles and Half-Lives of Ten Urinary Polycyclic Aromatic Hydrocarbon Metabolites after Dietary Exposure

“…Several studies, predominantly focused on 1-PYR, have been conducted to estimate half-life (t 1/2 ) from various exposure routes. The t 1/2 after inhalation exposure has been determined to be 6.0-29 h. [12][13][14] For ingestion exposure, the 1-PYR t 1/2 was reported to be 4.4-12 h. [15][16][17] For dermal absorption, the 1-PYR t 1/2 was estimated at 11.5-15 h. 17,18 In several occupational studies on workers exposed through both inhalation and dermal absorption, the average t 1/2 ranged 10.4-18 h. [19][20][21] Increasingly, PAH biomonitoring studies are being carried out using multiple biomarkers in addition to 1-PYR. Some biomarkers or metabolic patterns have been proposed to be associated with specific sources or risk factors due to the change of enzyme polymorphism.…”

Levels of 1-hydroxypyrene, symptoms and immunologic markers in vulcanization workers in the southern Sweden rubber industries

“…The urinary levels of 1-HP reflects the PAH exposure only during the last couple of days, due to the rather short half-life (18 h) of the metabolite (Buchet et al 1992). On the other hand, the occurrence of symptoms was asked for during 12 months.…”

The Relations between Polycyclic Aromatic Hydrocarbons Exposure and 1-OHP Levels as a Biomarker of the Exposure

“…creatinine) based on the regressions between the formation of an illness and the content of 1-OHP in urine, a higher lung carcinoma risk is estimated for the exposed workers in the carbon material production plant (18 (12).…”