Urinary Metabolites of Polycyclic Aromatic Hydrocarbons in Firefighters: A Systematic Review and Meta-Analysis

Baseline data and associations between urinary biomarkers of polycyclic aromatic hydrocarbons, blood pressure, hemogram, and lifestyle among wildland firefighters

Introduction

Available literature has found an association between firefighting and pathologic pathways leading to cardiorespiratory diseases, which have been linked with exposure to polycyclic aromatic hydrocarbons (PAHs). PAHs are highlighted as priority pollutants by the European Human Biomonitoring Initiative in occupational and non-occupational contexts.

Methods

This cross-sectional study is the first to simultaneously characterize six creatinine-adjusted PAHs metabolites (OHPAHs) in urine, blood pressure, cardiac frequency, and hemogram parameters among wildland firefighters without occupational exposure to fire emissions (> 7 days), while exploring several variables retrieved via questionnaires.

Results

Overall, baseline levels for total OHPAHs levels were 2 to 23-times superior to the general population, whereas individual metabolites remained below the general population median range (except for 1-hydroxynaphthalene+1-hydroxyacenaphtene). Exposure to gaseous pollutants and/or particulate matter during work-shift was associated with a 3.5-fold increase in total OHPAHs levels. Firefighters who smoke presented 3-times higher total concentration of OHPAHs than non-smokers (p < 0.001); non-smoker females presented 2-fold lower total OHPAHs (p = 0.049) than males. 1-hydroxypyrene was below the recommended occupational biological exposure value (2.5 μg/L), and the metabolite of carcinogenic PAH (benzo(a)pyrene) was not detected. Blood pressure was above 120/80 mmHg in 71% of subjects. Firefighters from the permanent intervention team presented significantly increased systolic pressure than those who performed other functions (p = 0.034). Tobacco consumption was significantly associated with higher basophils (p = 0.01-0.02) and hematocrit (p = 0.03). No association between OHPAHs and blood pressure was found. OHPAHs concentrations were positively correlated with monocyte, basophils, large immune cells, atypical lymphocytes, and mean corpuscular volume, which were stronger among smokers. Nevertheless, inverse associations were observed between fluorene and pyrene metabolites with neutrophils and eosinophils, respectively, in non-smokers. Hemogram was negatively affected by overworking and lower physical activity.

Conclusion

This study suggests possible associations between urinary PAHs metabolites and health parameters in firefighters, that should be further assessed in larger groups.

Association between co-exposure of polycyclic aromatic hydrocarbons and chronic obstructive pulmonary disease among the US adults: results from the 2013-2016 National Health and Nutrition Examination Survey

Although existing epidemiological studies have reported the relationship between single polycyclic aromatic hydrocarbon (PAH) exposure and chronic obstructive pulmonary disease (COPD), little is known about the impact of PAH mixture exposure on COPD. Therefore, we aimed to evaluate the associations of single and mixed exposures to PAHs with COPD in US adults using data from NHANES 2013-2016 by fitting three statistical methods, including multiple logistic regression, Bayesian kernel machine regression (BKMR), and quantile-based g-computation (qgcomp) models. This study included 1836 participants aged 40 and older. Multiple logistic regression showed that 2-FLU, 1-PHE, 1-PYR, and 2&3-PHE increased the risk of COPD after adjusting for all covariates. The BKMR model identified positive trends between PAH mixture and the risk of COPD in all adults and males when all PAHs were at or above their 55th percentile compared to all PAHs at their 50th percentile. The qgcomp model suggested that PAH co-exposure increased the risk of COPD (OR:1.44, 95%CI:1.09, 1.90) when each quartile increased in PAH mixture concentration, with 2-FLU having the highest weight. The combined impact also be observed in men. In conclusion, PAHs co-exposure was associated with a higher risk of COPD, especially in males, with the positive impact of 2-FLU being the most important.