Urinary Mercapturic Acids to Assess Exposure to Benzene and Other Volatile Organic Compounds in Coke Oven Workers

Reductions of multiple air pollutants from coking industry through technology improvements and their impacts on air quality and health risks in a highly industrialized region of China

The Beijing-Tianjin-Hebei (BTH) region, a highly industrialized area in China, boasts a concentration of coking plants that constitute a vital component of the steel industry. In recent years, the Chinese government has implemented measures including backward production capacity elimination (BPCE), ultra-low emission technology transformation (ULET), and deep treatment of volatile organic compounds (DTV), to promote technological progress in the coking industry and mitigate the impact of pollutant emissions. This study focuses on the emission trends, reduction effects of various measures, and the impact on air quality and human health in the regional scale. The findings reveal that in 2015, the emissions of PM, SO2, NOx and VOCs of the coking industry in BTH region were 29.15, 9.64, 26.62 and 82.99 Gg (1000 tons/year) respectively. However, by 2019, these emissions had significantly decreased by 19.95, 5.78, 18.69, and 22.53 Gg, respectively. Of these reductions, ULET contributed about 80.3 % of NOx and SO2, and 57.4 % of PM. Meanwhile, DTV and BPCE contributed 49.2 % and 50.7 % of VOCs emission reduction, respectively. Despite the improvement effect on PM2.5, SO2, and NO2 is limited, the substantial decrease in VOCs (particularly benzene) resulted in a significant reduction in the coking industry's contribution to the atmospheric benzene concentration, dropping from 15.9 % in 2015 to 11.6 % in 2019. Moreover, the lifetime cancer risk (LCR) contribution of benzene inhalation in the BTH region also decreased from 1.7 × 10-6 to 1.2 × 10-6. Looking ahead to 2025, the continued implementation of DTV will be expected to reduce VOCs emissions by 24.41Gg. This will bring the industry's contribution to the benzene concentration down to 6.8 % and the cancer risk of the population to an acceptable level (LCR < 1 × 10-6). Additionally, the deep treatment of VOCs in coking plants will significantly reduce the health risks faced by people living in the vicinity of the plants.

Exploring the internal exposome of seminal plasma with semen quality and live birth: A Pilot Study

Infertility is clinically defined as the inability to achieve pregnancy within 12 months of regular unprotected sexual intercourse and affects 15% of couples worldwide. Therefore, the identification of novel biomarkers that can accurately predict male reproductive health and couples' reproductive success is of major public health significance. The objective of this pilot study is to test whether untargeted metabolomics is capable of discriminating reproductive outcomes and understand associations between the internal exposome of seminal plasma and the reproductive outcomes of semen quality and live birth among ten participants undergoing assisted reproductive technology (ART) in Springfield, MA. We hypothesize that seminal plasma offers a novel biological matrix by which untargeted metabolomics is able to discern male reproductive status and predict reproductive success. The internal exposome data was acquired using UHPLC-HR-MS on randomized seminal plasma samples at UNC at Chapel Hill. Unsupervised and supervised multivariate analyses were used to visualize the differentiation of phenotypic groups classified by men with normal or low semen quality based on World Health Organization guidelines as well as by successful ART: live birth or no live birth. Over 100 exogenous metabolites, including environmentally relevant metabolites, ingested food components, drugs and medications, and metabolites relevant to microbiome-xenobiotic interaction, were identified and annotated from the seminal plasma samples, through matching against the NC HHEAR hub in-house experimental standard library. Pathway enrichment analysis indicated that fatty acid biosynthesis and metabolism, vitamin A metabolism, and histidine metabolism were associated sperm quality; while pathways involving vitamin A metabolism, C21-steroid hormone biosynthesis and metabolism, arachidonic acid metabolism, and Omega-3 fatty acid metabolism distinguished live birth groups. Taken together, these pilot results suggest that seminal plasma is a novel matrix to study the influence of the internal exposome on reproductive health outcomes. Future research aims to increase the sample size to validate these findings.

Biological Monitoring: Evidence for Reductions in Occupational Exposure and Risk

Aims: The aim of this publication is to explore occupational exposure trends from biological monitoring data collected over a period of more than 20 years. The data is stored within the HSE database, which holds more than 950,000 results from 120,000 workers in 8,000 companies. The data were collated for all biological monitoring results for lead, mercury, benzene, and hexamethylene diisocyanate exposures where there have been some regulatory drivers within the reported time period of the data searched.

Methods: Relevant results from sample analysed were extracted from the database and categorised by year from 1996 to the end of 2019 for individual blood lead results and individual urine results for mercury, benzene, and hexamethylene diisocyanate. Results were classed by broad occupational sector where possible. Data were reported graphically by analytical biomarker result (as 90th percentile (P90)) and number of samples per year as well as with overall summary statistics. To look at longer-term trends, results were also evaluated as P90 over 6-year periods.

Results: In the period 1996–2019, 37,474 blood lead, 11,723 urinary mercury, 9,188 urinary S-phenylmercapturic acid (SPMA, benzene metabolite) and 21,955 urinary hexamethylene diamine (HDA, metabolite of hexamethylene diisocyanate, HDI) samples were analysed and reported. Over the time period the blood lead concentrations saw the P90 reduce from 53 μg/dl 1996) to 24 μg/dl in 2019; the P90 urinary mercury levels reduced from 13.7 μmol/mol creatinine to 2.1 μmol/mol creatinine and the P90 urinary SPMA levels reduced from 133.7 μmol/mol creatinine to 1.7 μmol/mol creatinine. For HDI the P90 results reduced from 2 µmol HDA/mol creatinine in 1996–2000 to 0.7 in 2005–2010 but levels have since increased to 1.0 µmol HDA/mol creatinine (2016–2019).

Conclusion: There is strong evidence of reductions in exposure of GB workers to lead, benzene and mercury from the data presented here. These reductions may reflect the impact of national, regional and global regulatory action to reduce exposures however, the loss of high exposure industries (from either GB as a whole or just this dataset i.e., samples are being sent elsewhere) and the increase in automation or substitution also need to be considered as potential factors. The results for HDI show that whilst interventions can reduce exposures significantly, such initiatives may need to be refreshed at intervals to maintain the reductions in exposure. We have observed that exposures move between sectors over time. Waste and recycling (lead, mercury) and tunnelling through contaminated land (benzene) were sectors or tasks associated with significant exposures and may be increasingly areas of concern.

Evaluation of airborne exposure to volatile organic compounds of benzene, toluene, xylene, and ethylbenzene and its relationship to biological contact index in the workers of a petrochemical plant in the west of Iran

Nowadays, workers in petrochemical industry might be exposed to organic volatile compounds, including benzene, toluene, ethylbenzene, and xylene (BTEX). The aim of this study was to investigate the concentration of BTEX contaminations and the biological index in employees of petrochemical sites in the west of Iran. The study was conducted as a cross-sectional study on 30 stations and 60 inhalation and biological samples collected in winter and summer. The NIOSH 2549 and 1501 methods were used for sampling and analyzing the inhaled samples. Gas chromatography-mass spectrometry (GC-MS) equipped with flame ionization detector and high-performance liquid chromatography (HPLC) was used to measure the volatile contaminations. The results showed that the mean concentrations of benzene, toluene, and xylene were significantly different in summer and winter. Significant and strong correlations were observed between the concentrations of benzene, toluene, and xylene and the biological values (r > 0.7). Moreover, the concentration of benzene (β = 0.836), toluene (β = 0.718), and xylene (β = 0.786) predicted the changes in their biological values. Given the hazardous concentrations of benzene and toluene in industrial plants and the correlation of the concentration levels and biological values, management and control strategies should be implemented to eliminate and reduce the pollutants and the effects.