Human biomonitoring after chemical incidents and during short-term maintenance work as a tool for exposure analysis and assessment

Integrated environmental health assessment: Proposed approaches to exposure during chemical incidents

An integrated environmental health exposure assessment (IEHA) refers to the integration of human biomonitoring data (HBM) and environmental measurements and aims to optimize the exposure assessment process. Due to lack of data, this approach remains an issue during chemical incidents. This study aims to explore integrated exposure approaches for assessing human health risks during chemical incidents. Based on the Preferred Reporting Items of Systematic reviews and Meta-Analyses statement, a literature analysis was performed. A level of confidence ranging from 1 to 4 was established to define the quality and strength of data used to undertake an IEHA approach. Twenty-seven articles (n = 18) and texts (n = 9) from Europe (41%) and the United States (37%) were analyzed. Among the 18 scientific articles, 61% (n = 11) presented a quantitative approach and 17% (n = 3) presented a qualitative approach. Quantitative approaches must be based on accurate data, coupled with predictive models. Of all the scientific papers, 40% (n = 7) responded to a confidence level greater than or equal to 2. Uncertainties detected through the integrated exposure approaches were related to input data, analytical methods, and HBM reference value interpretations. During chemical incidents, direct measurements were the most relevant data. Few scientific studies have developed an integrated approach during emergency situations. However, when this was used, they presented a high level of confidence by defining levels of exposure that support decision-making processes. Despite the multiple approaches, there was a lack of guidelines allowing an integrated risk assessment to be performed during an emergency chemical exposure. Integr Environ Assess Manag 2024;20:481-497. © 2023 SETAC.

Human biomonitoring of low-level benzene exposures

Historically, benzene has been widely used in a large variety of applications. Occupational exposure limits (OELs) were set for benzene as it was found to be acutely toxic, causing central nervous system depression at high exposures. OELs were lowered when it was discovered that chronic exposure to benzene could cause haematotoxicity. After confirmation that benzene is a human carcinogen causing acute myeloid leukaemia and possibly other blood malignancies, OEL were further lowered. The industrial application of benzene as solvent is almost completely discontinued but it is still used as feedstock for the production of other materials, such as styrene. Occupational exposure to benzene may also occur since it is present in crude oil, natural gas condensate and a variety of petroleum products and because benzene can be formed in combustion of organic material. In the past few years, lower OELs for benzene in the range of 0.05-0.25 ppm have been proposed or were already established to protect workers from benzene-induced cancer. The skin is an important potential route of exposure and relatively more important at lower OELs. Consequently, human biomonitoring - which integrates all exposure routes - is routinely applied to control overall exposure to benzene. Several potential biomarkers have been proposed and investigated. For compliance check of the current low OELs, urinary S-phenylmercapturic acid (S-PMA), urinary benzene and blood benzene are feasible biomarkers. S-PMA appears to be the most promising biomarker but proper validation of biomarker levels corresponding to airborne benzene concentrations below 0.25 ppm are needed.

Quantification of Linrodostat and its metabolites: Overcoming bioanalytical challenges in support of a discovery Indoleamine 2,3 dioxygenase program

BMS-986205 (Linrodostat) is a small molecule inhibitor of Indoleamine 2, 3 dioxygenase (IDO) that is currently being evaluated in clinical trials for the oral treatment of advanced cancer. Initially, there were concerns regarding possible toxicity following administration, since BMS-986205 undergoes metabolism to form 4-chloroaniline. However, it was later determined that the downstream metabolites of 4-chloroaniline might be a greater concern. To evaluate the potential toxicity of these metabolites, a sensitive LC-MS/MS analytical method was needed to quantify both the parent compound and multiple metabolites. This presented a challenge since the method required the analysis of multiple analytes while still retaining the analytical sensitivity required to support studies. By utilizing a multi-function analytical method, we were able to quantify the necessary analytes using a complex LC-MS/MS-based method including the application of both negative and positive electrospray ionization.

Urinary biohazard markers in firefighters

Firefighters are the professional force at high risk of suffering potential health consequences due to their chronic exposure to numerous hazardous pollutants during firefighting activities. Unfortunately, determination of fire emission exposure is very challenging. As such, the identification and development of appropriate biomarkers is critical in meeting this need. This chapter presents a critical review of current information related with the use of different urinary biomarkers of effect and exposure in occupationally exposed firefighters over the last 25 years. Evidence suggests that urinary isoprostanes and mutagenicity testing are promising biomarkers of early oxidative stress. Data indicate that firefighters participating in firefighting activities present with increased urinary biomarkers of exposure. These include polycyclic aromatic hydrocarbons, heavy metals and metalloids, organo-chlorine and -phosphorus compounds, environmental phenols, phthalates, benzene and toluene. More studies are urgently needed to better evaluate firefighter occupational safety and health and to support the implementation of preventive measures and mitigation strategies to promote the protection of this chronically exposed group of workers.

Preparedness as a key factor for human biomonitoring programs after chemical incidents

BACKGROUND

Human biomonitoring (HBM) has been repeatedly recommended for and applied to post-incident chemical exposure assessment. The applicability of HBM and the validity of its results, however, closely depend on the existence and quality of preparatory measures such as information and instruction materials, sampling procedures, transport and storage facilities, and on the selection of appropriate biomarkers, sampling time, transport and storage conditions.

OBJECTIVE

To establish a standardized HBM program for emergency responders of a large chemical production site, considering the aforementioned aspects.

METHODS

An HBM program based on a comprehensive questionnaire, information and training of emergency responders, and availability of sampling material was established. The quantitative determination of metabolites of hazardous substances was carried out based on quality-controlled analytical methods.

RESULTS

The use of HBM after emergency operations was significantly increased immediately after the implementation of the program. Only in single cases, however, established HBM assessment values were exceeded. After one major incident, an increased exposure to benzene exceeding the internal action value was observed after firefighting and safeguarding.

SIGNIFICANCE

The experience with several minor and one major incident at a chemical production site suggests that the implementation of easily accessible and applicable routines is one paramount prerequisite for the success of HBM programs after chemical incidents.

Simultaneous determination of aromatic and chlorinated compounds in urine of exposed workers by dynamic headspace and gas chromatography coupled to mass spectrometry (dHS-GC-MS)

Mixed exposure to chemical products is a topical issue for occupational health and often includes exposure to volatile organic compounds (VOCs). As very few methods are available for evaluating these mixed exposures, the aim of this work was to develop a simple biomonitoring method to assess simultaneous occupational exposures to chlorinated and aromatic VOCs by analyzing the unmetabolized fraction of the VOCs in the urine of workers. Volatile organic compounds were analyzed using dynamic headspace gas chromatography coupled to mass spectrometry (dHS-GC-MS), and 11 unmetabolized urinary VOCs were measured into headspace phase, without any time-consuming pretreatment. Simultaneously, a standardized collection protocol was designed to avoid VOC losses or the contamination of urinary samples. The calibration samples were real urines, spiked with known amounts of the VOC mixtures studied. Test investigations were performed on potentially exposed workers in three factories in order to assess the effectiveness of both the collection protocol and analytical method. A satisfactory level of sensitivity was achieved, with limits of quantification (LOQ) between 10 and 15 ng/L obtained for all VOCs (except for styrene at 50 ng/L). Calibration curves were linear in the 0-20 μg/L range tested, with R² correlation coefficients of 0.991 to 0.998. At the lowest concentration tested (0.08 μg/L), within-day precision varied from 2.1 to 5.5% and between-day precision ranged from 2.7 to 8.5%. Sample stability at -20 °C required that urinary samples be analyzed within 3 months. Even though the urinary concentrations of VOCs used in the plants were mostly quite low, significant differences between post-shift and pre-shift were observed. In conclusion, a fast, sensitive, specific and easy-to-use method has been developed for extracting VOCs from human urine using dHS-GC-MS. The method described has proven to be reliable for assessing current occupational exposure to chlorinated and aromatic VOCs in France.

Short-term health effects in the general population following a major train accident with acrylonitrile in Belgium

BACKGROUND

Following a train derailment, several tons of acrylonitrile (ACN) exploded, inflamed and part of the ACN ended up in the sewage system of the village of Wetteren. More than 2000 residents living in the close vicinity of the accident and along the sewage system were evacuated. A human biomonitoring study of the adduct N-2-cyanoethylvaline (CEV) was carried out days 14-21 after the accident.

OBJECTIVES

(1) To describe the short-term health effects that were reported by the evacuated residents following the train accident, and (2) to explore the association between the CEV concentrations, extrapolated at the time of the accident, and the self-reported short-term health effects.

METHODS

Short-term health effects were reported in a questionnaire (n=191). An omnibus test of independence was used to investigate the association between the CEV concentrations and the symptoms. Dose-response relationships were quantified by Generalized Additive Models (GAMs).

RESULTS

The most frequently reported symptoms were local symptoms of irritation. In non-smokers, dose-dependency was observed between the CEV levels and the self-reporting of irritation (p=0.007) and nausea (p=0.007). Almost all non-smokers with CEV concentrations above 100pmol/g globin reported irritation symptoms. Both absence and presence of symptoms was reported by non-smokers with CEV concentrations below the reference value and up to 10 times the reference value. Residents who visited the emergency services reported more symptoms. This trend was seen for the whole range of CEV concentrations, and thus independently of the dose.

DISCUSSION AND CONCLUSION

The present study is one of the first to relate exposure levels to a chemical released during a chemical incident to short-term (self-reported) health effects. A dose-response relation was observed between the CEV concentrations and the reporting of short-term health effects in the non-smokers. Overall, the value of self-reported symptoms to assess exposure showed to be limited. The results of this study confirm that a critical view should be taken when considering self-reported health complaints and that ideally biomarkers are monitored to allow an objective assessment of exposure.