Human Exposure to Chlorinated Paraffins via Inhalation and Dust Ingestion in a Norwegian Cohort

Overlooked long-chain chlorinated paraffin (LCCP) contamination in foodstuff from China

Data on long-chain chlorinated paraffins (LCCPs) is extremely sparse, despite their use and emission are increasing with the phasing out of short-chain chlorinated paraffins (SCCPs). In this study, we analyzed chlorinated paraffins (CPs) in foodstuff samples (551 pooled samples, 93 items) divided into eight categories collected from Jinan, Shandong Province of China, by atmospheric-pressure chemical ionization quadrupole time-of-flight mass spectrometry (APCI-qToF-MS), to investigate the occurrence, contamination patterns and homologue patterns of LCCPs in foodstuff commonly consumed in traditional Chinese diet. LCCP intake through diet was estimated as well. LCCPs were detected in all pooled samples with geometric mean (GM) concentrations ranging from 1.8 to 21.9 ng/g wet weight (ng/g ww), contributing to 9-28% of the total CP mass in the studied foodstuff categories. The contamination patterns of LCCPs differed from SCCPs and medium-chain chlorinated paraffins (MCCPs), as reflected by the patterns of mass distribution, and by the lack of correlations between LCCP and S/MCCP concentrations in various foodstuff categories. The homologue profiles of LCCPs were extremely complex and diverse, with frequent detection of C_30-36Cl_2-15 very-long-chain chlorinated paraffin (vLCCP) congeners. The homologue profiles of eggs stood out for their high abundance of C_18-22Cl_9-13 LCCP congeners. LCCPs contributed 6.0-25.2% (8.9% for median estimation) to the estimated dietary intake (EDI) for total CPs through diet based on estimations using different percentiles of CP concentrations. The median estimate of dietary LCCP intake for adults in Jinan was 287.9 ng/kg_bw/day, reaching ~10- to 100-fold of that in Sweden and Canada. Considering the continuing production, use and emission of LCCPs, as well as the similar toxicity effects induced by LCCPs as SCCPs and MCCPs, attention should be paid to the health risk posed by LCCPs, or all CPs as a class of contaminants.

Guidance on the Application of Polyurethane Foam Disk Passive Air Samplers for Measuring Nonane and Short-Chain Chlorinated Paraffins in Air: Results from a Screening Study in Urban Air

This study provides guidance on using polyurethane foam-based passive air samplers (PUF-PASs) for atmospheric nonane chlorinated paraffins (C₉-CPs) and short-chain CPs (SCCPs) and reports SCCP concentrations in air in the Greater Toronto Area (GTA), Canada. We estimated the partition coefficients between PUF and air (K_PUF-A) and between octanol and air (K_OA) for C₉-CP and SCCP congeners using the COSMO-RS method, so that PUF disk uptake profiles for each formula group could be calculated. We then measured SCCP concentrations in PUF disk samples collected from distinct source sectors in urban air across the GTA. Concentrations in samplers were used to calculate C₉-CP and SCCP concentrations in air and the PUF disk uptake profiles revealed that time-weighted linear phase sampling was possible for congeners having log K_OA values greater than 8.5. The highest SCCP concentrations, with an annual average concentration of 35.3 ng/m³, were measured at the industrial site, whereas lower but comparable SCCP concentrations were found in residential and background sites, with annual averages of 7.73 and 10.5 ng/m³, respectively. No consistent seasonal variation in SCCP concentrations was found in the six distinct source sectors. Direct measurements of K_PUF-A and K_OA values as a function of temperature could be used to increase accuracy in future studies.

Optimization of a low flow sampler for improved assessment of gas and particle bound exposure to chlorinated paraffins

An optimized low volume sampler was developed to determine both gas- and particle bound concentrations of short and medium-chain chlorinated paraffins (S/MCCPs). Background contamination was limited by the sampler design, providing method quantification limits (MQLs) at least two orders of magnitude lower than other studies within the gas (MQL: 500 pg (ΣSCCPs), 1.86 ng (ΣMCCPs)) and particle (MQL: 500 pg (ΣSCCPs), 1.72 ng (ΣMCCPs) phases. Good repeatability was observed between parallel indoor measurements (RSD ≤ 9.3% (gas), RSD ≤ 14% (particle)) with no breakthrough/saturation observed after a week of continuous sampling. For indoor air sampling, SCCPs were dominant within the gas phase (17 ± 4.9 ng/m³) compared to MCCPs (2.7 ± 0.8 ng/m³) while the opposite was observed in the particle bound fraction (0.28 ± 0.11 ng/m³ (ΣSCCPs) vs. 2.7 ± 1.0 ng/m³ (ΣMCCPs)). Only SCCPs in the gas phase could be detected reliably during outdoor sampling and were considerably lower compared to indoor concentrations (0.27 ± 0.10 ng/m³). Separation of the gas and particle bound phase was found to be crucial in applying the appropriate response factors for quantification based on the deconvoluted S/MCCP sample profile, thus avoiding over- (gas phase) or underestimation (particle phase) of reported concentrations. Very short chain chlorinated paraffins (vSCCPs, C₅-C₉) were also detected at equal or higher abundance compared to SCCP congener groups (C₁₀-C₁₃) congener groups, indicating an additional human indoor inhalation risk.