Polycyclic aromatic hydrocarbon exposure burden: Individual and mixture analyses of associations with chronic obstructive pulmonary disease risk.

Accumulating data demonstrate that polycyclic aromatic hydrocarbons (PAH) exposure is linked to compromised respiratory diseases. This study aimed to analyze urinary PAH metabolites and their associations with chronic obstructive pulmonary disease (COPD) in a sample size of 3015 subjects from a total population of 50,588 from the National Health and Nutrition Examination Survey (NHANES) in 2007-2016. Results showed that the most predominant metabolite was 1-Hydroxynaphthalene (1-NAP, 84%) with a geometric mean concentration of 50,265 ng/L, followed by its homologue 2-NAP (10%), both of which arose from sources including road emission, smoking and cooking. Multiple logistic regression showed that seven of the ten major PAH metabolites were correlated with increased COPD risk: including 1-NAP (OR: 1.83, 95%CI: 1.25, 2.69), 2-Hydroxyfluorene (2-FLU, OR: 2.29, 95%CI: 1.42, 3.68) and 1-Hydroxyphenanthrene (1-PHE, OR: 2.79, 95%CI: 1.85, 4.21), when compared to the lowest tertile after adjusted for covariates. Total exposure burden per PAH congener sub-group demonstrated persistent positive correlation with COPD for ∑PHE (OR: 1.80, 95%CI: 1.34, 2.43) and ∑FLU (OR: 2.74, 95%CI: 1.77, 4.23) after adjusted for covariates. To address the contribution of PAH exposure as mixture towards COPD, weighted quantile sum (WQS) regression analyses revealed that 1-NAP, 9-Hydroxyfluorene (9-FLU), 3-Hydroxyfluorene (3-FLU) and 1-PHE were among the top contributors in the associations with COPD. Our results demonstrate the contemporary yet ongoing exposure burden of PAH exposure for over a decade, particularly towards NAPs and FLUs that contribute significantly to COPD risk, calling for more timely environmental regulation.

Are human exposure assessment the same for non-persistent organic chemicals? -from the lens of urinary variability and predictability.

Assessment of human exposure to mixtures of non-persistent chemicals from food matrices and consumer products requires accurate characterization and estimation of their preceding exposure levels, and assessment sampling approaches for these varying chemicals remain disputable. Here, we used high-throughput targeted method to quantify urinary concentrations of 59 most common non-persistent chemicals (6 parabens, 14 bisphenols, 1 triclosan, 7 benzophenones, 2 dichlorophenols, 13 phthalate metabolites and 16 antioxidants) in 158 consecutive spot samples from 11 participants over three consecutive days, 33 samples of which were first morning voids (FMVs). We found 49 chemicals with detection frequencies over 70 % in all urine samples. Principal component analyses showed greater inter-person variations than each person's inter-day variations. Intraclass correlation coefficient (ICC) to assess the reproducibility of targeted chemicals demonstrated that regardless of sampling approaches, dichlorophenols, most parabens, benzophenones and triclosan showed moderate to high reproducibility (0.445 < ICC < 0.969), with relatively high predictive power of FMVs for 24-h collections. Notably, most phthalates, bisphenols and antioxidants showed low ICC values. Together, our work demonstrates that FMV samples may be adequate for assessing human exposure to parabens, benzophenones, triclosan and dichlorophenols, whereas multiple consecutive urine collections may be advantageous for evaluating exposure to most phthalates, bisphenols and antioxidants.

Is e-waste a source of phthalate and novel non-phthalate plasticizers? A comparison study on indoor dust.

Nine traditional phthalate plasticizers and 33 novel non-phthalate plasticizers were determined in indoor dust from a typical e-waste recycling area. The median concentrations ranged from Dakeng > Baihetang > Shiding > Jieyang, which was consistent with the local e-waste dismantling activities and supported by polybrominated diphenyl ethers (PBDEs) levels. The correlations between chemical levels and the indicators indicated that most phthalates and non-phthalate plasticizers in the dust, might not be primarily influenced by e-waste emission sources. Additionally, the estimated median human exposures of phthalates and non-phthalates via dust ingestion were 30.6 and 1.82 ng/kg/day for adults, and 299 and 17.8 ng/kg/day for toddlers respectively, indicating negligible health risks.