Concentrations of selected monohydroxy polycyclic aromatic hydrocarbons across various stages of glomerular function

Enrichment of polycyclic aromatic hydrocarbon metabolizing microorganisms on the oral mucosa of tobacco users

Certain soil microbes resist and metabolize polycyclic aromatic hydrocarbons (PAHs). The same is true for a subset of skin microbes. In the human mouth, oral microbes have the potential to oxidize tobacco PAHs, thereby increasing these chemicals' ability to cause cancer of adjacent epithelium. We hypothesized that we could identify, in smokers, the oral mucosal microbes that can metabolize PAH. We isolated bacteria and fungi that survived long-term in minimal media with PAHs as the sole carbon source, under aerobic conditions, from the oral mucosa in 17 of 26 smokers and two of 14 nonsmokers. Of bacteria genera that survived harsh PAH exposure in vitro, most were found at trace levels, except for Staphylococcus, Actinomyces, and Kingella, which were more abundant. Two PAH-resistant strains of Candida albicans (C. albicans) were isolated from smokers. C. albicans was a prime candidate to contribute to carcinogenesis in tobacco users as it is found orally at high levels in tobacco users on the mucosa, and some Candida species can metabolize PAHs. However, when C. albicans isolates were tested for metabolism of two model PAH substrates, pyrene and phenanthrene, they were not capable, suggesting they cannot metabolize PAH under the conditions used. In conclusion, evidence for large scale microbial degradation of tobacco PAHs under aerobic conditions on the oral mucosa remains lacking, though nonabundant PAH metabolizers are certainly present.

Association of chronic kidney disease with exposure to polycyclic aromatic hydrocarbons in the US population

Polycyclic aromatic hydrocarbons (PAHs) are environmental pollutants formed from the incomplete combustion of carbon-containing products. Exposure can occur through ingestion or inhalation and has been linked to depression, stroke, liver disease, asthma, diabetes, heart failure, and cancer. Few studies have investigated the association between exposure to PAHs and chronic kidney disease (CKD) in humans. This study aims to investigate the association between seven urinary PAH concentrations (1-hydroxynaphthalene, 2-hydroxynaphthalene, 3-hydroxyfluorene 2-hydroxyfluorene, 1-hydroxyphenanthrene, 1-hydroxypyrene, and 2 & 3-hydroxyphenanthrene) and CKD in the US adult population. A cross-sectional analysis using the 2015-2016 National Health and Nutrition Examination Survey (NHANES) dataset was conducted. CKD was defined with estimated glomerular filtration rate (eGFR) and albumin to creatinine ratio (ACR). Participants with an eGFR < 60 ml/min/1.73m² or ACR > 30 mg/gm were considered to have CKD. A specialized complex survey design analysis package using R version 4.0.3 was used in the data analysis. Multivariate logistic regression was used to study the correlation between seven forms of urinary PAH concentrations and CKD associated with abnormal eGFR or ACR. The models were adjusted for lifestyle and demographic factors. The study included a total of 4117 adults aged ≥ 20 years, with 49.6% males and 50.4% females. Urinary 2-hydroxynaphthalene (OR: 1.600, 95% CI: 1.141, 2.243) was significantly associated with an increased odds of CKD; the other six forms of urinary PAHs were not associated with CKD. Non-Hispanic Black (OR: 1.569, 95% CI: 1.168, 2.108), age of 60 years and older (OR: 2.546, 95% CI: 1.865, 3.476), and BMIs of underweight (OR: 2.386, 95% CI: 1.259, 4.524) and obese (OR: 1.407, 95% CI: 1.113, 1.778) all had significantly increased odds for CKD. Our study concluded that urinary 2-hydroxynaphthalene, a form of PAH, is significantly associated with CKD.

Evaluation of hydroxylated metabolites of polycyclic aromatic hydrocarbons and biomarkers of early kidney damage in indigenous children from Ticul, Yucatán, Mexico

Polycyclic aromatic hydrocarbons (PAHs) are environmental persistent chemicals, produced by the incomplete combustion of solid fuels, found in smoke. PAHs are considered carcinogenic, teratogenic, and genotoxic. Children are susceptible to environmental pollutants, particularly those living in high-exposure settings. Therefore, the main objective of this study was to evaluate the exposure to PAHs through hydroxylated metabolites of PAHs (OH-PAHs), 1-hydroxynaphtalene (1-OH-NAP), and 2-hydroxynaphtalene (2-OH-NAP); 2-,3-, and 9-hydroxyfluorene (2-OH-FLU, 3-OH-FLU, 9-OH-FLU); 1-,2-,3-, and 4-hydroxyphenanthrene (1-OH-PHE, 2-OH-PHE, 3-OH-PHE, 4-OH-PHE); and 1-hydroxypyrene (1-OH-PYR), as well as kidney health through biomarkers of early kidney damage (osteopontin (OPN), neutrophil gelatinase-associated lipocalin (NGAL), α1-microglobulin (α1-MG), and cystatin C (Cys-C)) in children from an indigenous community dedicated to footwear manufacturing and pottery in Ticul, Yucatán, Mexico. The results show a high exposure to PAHs from the found concentrations of OH-PAHs in urine in 80.5% of the children in median concentrations of 18.4 (5.1-71.0) μg/L of total OH-PAHs, as well as concentrations of kidney damage proteins in 100% of the study population in concentrations of 4.8 (3-12.2) and 7.9 (6.5-13.7) μg/g creatinine of NGAL and Cys-C respectively, and 97.5% of the population with concentrations of OPN and α1-MG at mean concentrations of 207.3 (119.8-399.8) and 92.2 (68.5-165.5) μg/g creatinine. The information provided should be considered and addressed by the health authorities to establish continuous biomonitoring and programs to reduce para-occupational exposure in the vulnerable population, particularly children, based on their fundamental human right to health.