Contamination of firefighters' merino wool and mixed fibre sweater and hood undergarments with polycyclic aromatic hydrocarbons

Abstract

Background: Several authors have studied contamination of polycyclic aromatic hydrocarbons (PAHs) found on the outer gears of firefighters, but to our knowledge, none have investigated merino wool and mixed fibre undergarments used underneath the protective turnout gear. We therefore performed a comprehensive study regarding selected PAHs in pieces cut out from different areas of firefighter's sweaters and hood used in real fires and laundered after each use.

Method: Hoods (38) and sweaters (58) were donated by 3 fire departments and from these garments 558 pieces of fabric were cut out. Extracts of the fabric pieces were analysed by liquid chromatography with ultraviolet and fluorescence detection for 7 PAHs: anthracene, benzo[a]pyrene, chrysene, fluoranthene, naphthalene, phenanthrene, and pyrene. In addition, a small study was performed to examine the removal of PAHs from sweaters during laundry.

Results: Trace amounts of anthracene, benzo[a]pyrene, fluoranthene, and pyrene were detected both in merino wool and mixed fibre sweaters and hoods with highest concentrations for the hoods and lowest for the back of the sweaters. Highest concentration was found for the forehead position of the hoods. Significantly higher concentrations of PAHs were found in both hoods and sweaters containing the textile meta-aramid. Laundering reduced the amount of PAHs-in the sweaters but not completely.

Conclusion: Trace levels of benzo[a]pyrene and 3 other PAHs could be found in firefighters routine laundered undergarments. Cleaning reduced the PAH levels but not completely, and textiles with meta-aramid contained more PAHs than those without. Merino wool and mixed fibre undergarments are used in many countries and the results are valuable outside this study.

Keywords: PAH; benzo[a]pyrene; fire-department; garments; linear mixed tobit regression model; merino wool; meta-aramid; protective gear; turnout gear.

Fig. 1.

Illustration of the positions of the fabric pieces cut out from the front and back of the sweater (1A) and the hoods (1B) belonging to part I of the study. Figure 1C indicate the positions cut out before and after laundry in part II of the study.

Fig. 2.

Scatter plots illustrating the relationship between fluoranthene and pyrene in hoods and sweaters. The fitted line is solid black, and the 95% confidence intervals (CI) have dashed lines.

Fig. 3.

Box plot of PAH concentrations (ng/piece of fabric) in sweaters used once (new), used several times (old) and before and after laundering. The boxes contain the measurements between the upper and lower quartiles, the solid and dashed lines inside the boxes are median and mean respectively. The whiskers are the interquartile range times 1.5 from the box. Colours indicate the type of PAH and hatched boxes laundering.