PIG-A gene mutation as a genotoxicity biomaker in polycyclic aromatic hydrocarbon-exposed barbecue workers

Background The PIG-A gene mutation assay is a valuable tool for measuring in vivo gene mutations in blood cells. The human PIG-A assay, used as a potential genotoxicity biomarker, is minimally invasive, sensitive, and cost-efficient; however, the relationship between carcinogen exposure and PIG-A mutations is not well understood. Methods We investigated the genotoxic effect of red blood cells using PIG-A assay and lymphocyte cytokinesis-block micronucleus test in barbecue restaurant workers (N = 70) exposed to polycyclic aromatic hydrocarbons (PAHs) and self-identified healthy control subjects (N = 56). Urinary PAH metabolites were measured to evaluate internal exposure levels. Results Multivariate Poisson regression showed that the PAH-exposed workers exhibited significantly higher PIG-A mutant frequency (MF) (8.04 ± 6.81 × 10− 6) than did the controls (5.56 ± 5.26 × 10− 6) (RR = 0.707, 95% CI: 0.615–0.812, P < 0.001). These results indicate that PAH exposure is a risk factor for elevated PIG-A MF. The frequencies of micronuclei (MN) and nuclear buds (NBUD) in the PAH-exposed workers (MN: 3.06 ± 2.07 ‰, NBUD: 1.38 ± 1.02 ‰) were also significantly higher than in the controls (MN: 1.46 ± 0.64 ‰, P < 0.001; NBUD: 0.70 ± 0.60 ‰, P < 0.001). Additionally, PIG-A MFs showed better associations with several urinary hydroxylated PAH metabolites (P2-OH-Flu = 0.032, r2-OH-Flu = 0. 268; P2-OH-Phe = 0.022, r2-OH-Phe = 0.286; P3-OH-Phe = 0.0312, r3-OH-Phe = 0.270; P4-OH-Phe = 0.018, r4-OH-Phe = 0.296), while the increase in MN, NPB, and NBUD frequencies was not associated with any OH-PAH metabolites; and high-PAH-exposed workers showed the highest PIG-A MFs. Furthermore, there was a significant association between PIG-A MF and PAH exposure levels (Chi-square test for trend, P = 0.006). Conclusions Our results indicate that an increase in PIG-A MF in barbecue workers could reflect the response to PAH exposure, providing evidence of its potential as a genotoxicity biomarker in human risk assessment.

Dose–response relationships between polycyclic aromatic hydrocarbon exposure and blood cell counts among coke oven workers: a sex-stratified analysis

ObjectivesTo explore sex differences and dose–response relationships between nine urinary polycyclic aromatic hydrocarbon (PAH) metabolites and neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) and complete blood counts among coke oven workers.Design and settingA cross-sectional study with stratified sex was conducted in Shanxi, China.ParticipantsA total of 458 male workers and 226 female workers were selected.Primary and secondary outcome measuresGeneral linear models, p values for trend tests and natural cubic spline models were used to explore the dose–response relationships between nine urinary PAH metabolites and NLR, PLR and complete blood counts.ResultCompared with male workers, female workers had lower exposure level of PAH (0.95 ng/mL vs 1.38 ng/mL). Only among female workers did we observe that a 1-unit increase in lg(1-OHPyr) was related to a 0.149 (95% CI: 0.055 to 0.242; p for trend=0.041) and 0.103 (95% CI: 0.025 to 0.181; p for trend=0.007) increase in lg(NLR) and lg(PLR), and a 0.116 (95% CI: −0.179 to –0.054; p for trend=0.007) decrease in lg(lymphocyte counts (LYMs)). A 1-unit increase in lg(2-OHNap) was related to a 0.045 (95% CI: 0.003 to 0.086; p for trend=0.037) increase in lg(PLR) and a 0.029 (95% CI: −0.056 to –0.002; p for trend=0.030) and 0.016 (95% CI: −0.029 to –0.003; p for trend=0.010) decrease in lg(white blood cell counts (WBCs)) and lg(haemoglobin (HGB)).ConclusionFemale workers’ NLR, PLR, WBCs, HGB and LYMs may be more susceptible than those of male workers when affected by PAH.

Association between Polycyclic Aromatic Hydrocarbon Exposure and Diarrhea in Adults

Objective: Polycyclic aromatic hydrocarbons (PAHs) are not only natural but also anthropogenic contaminants that exist in many places in the environment. Human beings often accidentally ingest PAHs via smoking. Furthermore, smoking may increase the risk of bowel disorder, including diarrhea and other gastrointestinal problems. Therefore, PAH exposure is hypothesized to be related to diarrhea risk. This study discusses the association between diarrhea and PAH exposure in the United States adult population. Method: 10,537 participants from the National Health and Nutrition Examination Survey (NHANES 2001–2006) were involved in this cross-sectional analysis. Bowel disorders were assessed via examination of stool frequency and stool type. The concentrations of urinary PAH metabolites were used to evaluate PAH exposure. The association between bowel habits and PAH exposure was assessed using a multivariate logistic regression model with covariate assessment of gender, age, race, liver function, kidney function, and common chronic health diseases. Results: All PAH metabolites except 1-hydroxynaphthalene, 1-hydroxypyrene, and 9-hydroxyfluorene were substantially correlated with an increased risk of diarrhea (p < 0.05) after modification of relevant covariables. This study also revealed significant association in the group of females (p < 0.05). Furthermore, all PAH metabolites except 1-hydroxynaphthalene, 2-hydroxyphenanthrene, 1-hydroxypyrene, and 9-hydroxyfluorene show significantly positive association in the non-obesity group (BMI < 30, p < 0.05). Conclusions: PAH exposure is highly associated with risk of bowel disorders among the adult population in the United States, especially in female and non-obesity populations. More research is necessary to shed light on the pathophysiological mechanisms associated to PAH exposure and diarrhea.

Clinical Relevance of Urine Flow Rate and Exposure to Polycyclic Aromatic Hydrocarbons

Background: Polycyclic aromatic hydrocarbon (PAH) metabolites have received increasing attention because several of these organic substances are highly carcinogenic or mutagenic. Exposure to PAHs is associated with many harmful health effects; however, we are not aware of any study that has explored the exposure to PAHs and urinary conditions in the general population. The present work aimed to investigate the correlation among PAH and urine flow rate (UFR). Method: Cross-sectional data from the National Health and Nutrition Examination Survey (NHANES) 2009–2012 were used in our study. A total of 4172 participants and a total of nine PAH metabolites were examined. The UFR was measured as the amount of urine excreted in a period of time (mL/h). Several covariates were adjusted in linear regression models. Result: After adjusting for variables, the PAH metabolites in urine showed a significant correlation with UFR. Dose-dependent associations between PAH metabolites in the urine and UFR were also found. Higher quartiles of PAH metabolites in urine exhibited higher regression coefficients. Conclusion: Our study highlighted that PAH metabolites in urine had a strong association with decreased UFR in the US adult population. These findings support the possibility that PAH exposure is related to bladder dysfunction. Further prospective studies are warranted.

Evaluation of fireground exposures using urinary PAH metabolites

Background Firefighters have increased cancer incidence and mortality rates compared to the general population, and are exposed to multiple products of combustion including known and suspected carcinogens. Objective The study objective was to quantify fire response exposures by role and self-reported exposure risks. Methods Urinary hydroxylated metabolites of polycyclic aromatic hydrocarbons (PAH-OHs) were measured at baseline and 2–4 h after structural fires and post-fire surveys were collected. Results Baseline urine samples were collected from 242 firefighters. Of these, 141 responded to at least one of 15 structural fires and provided a post-fire urine. Compared with baseline measurements, the mean fold change of post-fire urinary PAH-OHs increased similarly across roles, including captains (2.05 (95% CI 1.59–2.65)), engineers (2.10 (95% CI 1.47–3.05)), firefighters (2.83 (95% CI 2.14–3.71)), and paramedics (1.84 (95% CI 1.33–2.60)). Interior responses, smoke odor on skin, and lack of recent laundering or changing of hoods were significantly associated with increased post-fire urinary PAH-OHs. Significance Ambient smoke from the fire represents an exposure hazard for all individuals on the fireground; engineers and paramedics in particular may not be aware of the extent of their exposure. Post-fire surveys identified specific risks associated with increased exposure.

BILIARY PAH METABOLITES IN FISH FROM THE HIGHLY IMPACTED GUANABARA BAY, IN SOUTHEASTERN BRAZIL, DETERMINED BY FIXED AND SYNCHRONOUS FLUORESCENCE SPECTROSCOPY

Guanabara Bay (GB) covers the metropolitan region of the state of Rio de Janeiro in Brazil. GB is subject to heavy contamination by polycyclic aromatic hydrocarbons (PAHs), from intense oil activities, which pose an ecotoxicological threat. The aim of this study is to implement and optimize a fluorescence methodology for the determination of biliary PAH metabolites in fish species (burrfish and whitemouth croaker), in order to evaluate biliary PAH metabolites as a biomarker of exposure. Fish were sampled from GB and a control region. Naphthalene, pyrene and benzo(a)pyrene metabolites were determined by Fixed Fluorescence Method (FF), while 1-hydroxypyrene was assessed by Synchronous Fluorescence Spectroscopy (SFS). The implementation and optimization of the FF and SFS methods allowed the determination and evaluation of the exposure of these species to PAHs of pyrogenic and petrogenic origin. Biliary PAH metabolite determinations was proven to be a useful tool for environmental monitoring contamination assessments.

Association between urinary polycyclic aromatic hydrocarbons and hypertension in the Korean population: data from the Second Korean National Environmental Health Survey (2012–2014)

Polycyclic aromatic hydrocarbons (PAHs) are environmental and occupational pollutants derived from incomplete combustion of organic materials, including wood and fossil fuels. Epidemiological studies have evaluated the association between PAH exposure and hypertension or cardiovascular disease in the general population, but the evidence is limited. In this study, we evaluated the association between urinary PAH metabolites and hypertension in the Korean adult population. A total of 6478 adults who participated in the Second Korean National Environmental Health Survey (2012–2014) were included. The differences in urinary concentrations of four PAH metabolites, including 1-hydroxypyrene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, and 2-naphthol, were compared according to hypertension status using a general linear model. Adjusted odds ratios (aORs) for hypertension were calculated according to the quartile groups of urinary PAH metabolites after adjusting for age, sex, body mass index (BMI), smoking, and alcohol consumption in multiple logistic regression analyses. The estimated mean concentrations of urinary 1-hydroxyphenanthrene were significantly higher in the hypertension group than in the non-hypertension group. In 1-hydroxyphenanthrene, the OR for hypertension was significantly higher in the third and fourth quartile groups than in the first quartile group (third: OR 1.707, 95% CI 1.203–2.423, fourth: OR 1.604, 95% CI 1.158–2.223). No significant associations were detected for the other metabolites. Our results suggest an association between exposure to PAHs and hypertension in a Korean adult population. Further studies are required to evaluate the effects of low-dose long-term exposure to PAHs on hypertension and cardiovascular disease.

Detrimental association between quadriceps strength and exposure to polycyclic aromatic hydrocarbons in elderly adults

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants primarily from the incomplete combustion of organic materials. Myriads of studies have reported the associations between PAH exposure with several adverse health outcomes. However, no previous study had explored the relationship between PAH exposure with muscle strength in the elderly population. In the present study, we included 473 elderly adults who were obtained from the US National Health and Nutrition Examination Survey (NHANES) (2001–2006). PAH metabolites were measured in urine samples. Muscle strength was determined as the isokinetic strength of the quadriceps. Pertinent variables were analyzed by various standard measurements. The association between PAH exposure and muscle strength was examined using multivariable linear regression models. After fully adjusting for covariables, PAH metabolites had a negative relationship with muscle strength, especially 3-fluorene (β = –0.021, 95% CI: –0.042, 0.000) and 2-fluorene (β = –0.020, 95% CI: –0.034, –0.005). Notably, the relationship remained significant in males, but not in females. PAH exposure is associated with decreased muscle strength in the US elderly population. Further studies are needed to bring to light the underlying mechanisms for these findings. In addition, it is important to provide interventions and determine strategies for treating the adverse impact of PAH exposure on dynapenia. Novelty PAH exposure is associated with decreased muscle strength in elderly adults. The adverse impact remains in males.