Quantitative macroinvertebrate bioassessment in seasonally astatic aquatic habitats, Part I. Quantitative method.

Seasonally astatic aquatic habitats are important ecologically, municipally, and agriculturally. Regulatory agencies and conservation organizations have developed various plans for protecting or constructing temporary wetlands, resulting in habitat monitoring requirements, particularly as relates to restoration and constructed habitats. Unfortunately, there has been no effort to develop a unified, consistent method for wetland biological monitoring. This is particularly true for habitats important in a regulatory sense. We conducted macroinvertebrate bioassessment in constructed vernal pools in California, USA, to assess habitat functionality. This tool is modified from aquatic bioassessment; a primary tool of regulatory agencies in measuring habitat health and water quality and should be equally applicable to seasonally astatic wetlands globally.

Quantitative macroinvertebrate bioassessment in seasonally astatic aquatic habitats, Part II. Applying the method.

Seasonally astatic aquatic habitats are important ecologically, municipally, and agriculturally. Regulatory agencies and conservation organizations have developed various plans for protecting or constructing temporary wetlands, resulting in habitat monitoring requirements, particularly as relates to restoration and constructed habitats. Unfortunately, there has been no effort to develop a unified, consistent method for wetland biological monitoring. In Part I, we presented a quantifiable, replicable method for assessing seasonally astatic wetlands, which would allow for direct comparison between individual wetlands, wetland sites, and wetland types. Here in Part II, we apply the method and present the results from more than a decade of a data on two disparate sites that support California vernal pool habitats. These habitats include natural, restored, and constructed vernal pools. Our results demonstrate that the method we present yields reliable, statistically useful, and actionable data and provides a better method for assessing astatic wetland ecological health and the persistence of federally listed vernal pool crustaceans than other methods so far employed.

A novel method for the accurate quantification of two isomeric mercapturic acids of 1,3-dichlorobenzene in human urine using isotope dilution online-SPE-LC-MS/MS.

1,3-dichlorobenzene (1,3-DCB) is an aromatic solvent that might be formed during thermal decomposition of bis(2,4-dichlorobenzoyl)peroxide used as initiator in silicone rubber production with many workers exposed worldwide. During metabolism of 1,3-DCB, two isomeric mercapturic acids can be formed from ring oxidation of 1,3-DCB in the liver, namely 2,4-dichlorophenylmercapturic acid (24CPhMA) and 3,5-dichlorophenylmercapturic acid (35CPhMA). These urinary mercapturic acids might serve as biomarkers of the toxicologically relevant absorbed dose of 1,3-DCB and have not been determined so far. Thus, we were aimed to develop an analytical method for quantification of these biomarkers. Authentic standards of both mercapturic acids as well as deuterium-labelled analogues were self-synthesized. A method for the quantification of both CPhMAs in human urine using online-SPE LC/MS/MS was developed and validated with an LOQ of 0.1 ng mL-1 for both CPhMAs. The analytes were extracted from urine by online-SPE on a restricted access material phase, transferred to the analytical column and quantified by tandem mass spectrometry. Interday (n = 6) and Intraday (n = 10) precision for both CPhMAs ranged from 1.7 to 4.3 % with accuracies between 99.4 and 109.9 % at concentrations of 0.6 and 3 ng mL-1. We applied the method on post-shift urine samples of 16 workers of the silicone rubber industry with occupational exposure to 1,3-DCB. Both CPhMAs were above LOQ in 15 of 16 urine samples with median levels (range) for 24CPhMA and 35CPhMA of 1.64 ng mL-1 (<0.1 - 8.2 ng mL-1) and 3.98 ng mL-1 (0.36 - 24.1 ng mL-1), respectively. This is the first report on specific urinary mercapturic acids of 1,3-DCB in humans. Our results show that ring oxidation of 1,3-DCB is considered to be a toxicologically relevant metabolic pathway in humans. This might improve risk assessment of 1,3-DCB-emissions in silicone rubber industry.

An Automated Micro Solid-Phase Extraction (µSPE) Liquid Chromatography-Mass Spectrometry Method for Cyclophosphamide and Iphosphamide: Biological Monitoring in Antineoplastic Drug (AD) Occupational Exposure.

Despite the considerable steps taken in the last decade in the context of antineoplastic drug (AD) handling procedures, their mutagenic effect still poses a threat to healthcare personnel actively involved in compounding and administration units. Biological monitoring procedures usually require large volumes of sample and extraction solvents, or do not provide adequate sensitivity. It is here proposed a fast and automated method to evaluate the urinary levels of cyclophosphamide and iphosphamide, composed of a miniaturized solid phase extraction (µSPE) followed by ultrahigh-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The extraction procedure, developed through design of experiments (DoE) on the ePrep One Workstation, required a total time of 9.5 min per sample, with recoveries of 77-79% and a solvent consumption lower than 1.5 mL per 1 mL of urine sample. Thanks to the UHPLC-MS/MS method, the limits of quantification (LOQ) obtained were lower than 10 pg/mL. The analytical procedure was successfully applied to 23 urine samples from compounding wards of four Italian hospitals, which resulted in contaminations between 27 and 182 pg/mL.

Is Routine Post-operative Biological Laboratory Assessment Necessary After Sleeve Gastrectomy?

BACKGROUND: Incidence of post-operative complications after sleeve gastrectomy (SG) is low. However, the early identification of these complications remains crucial. Here, we report the impact of routine laboratory monitoring for the early diagnosis of complications after SG. MATERIAL AND METHODS: From January 2018 to December 2019, all consecutive patients who underwent primary SG (n = 457) were included. This was a comparative study of patients undergoing primary SG. Patients were divided into two groups: one group with routine laboratory monitoring performed at postoperative day (POD) 1 and 3 (LAB group) and another group without routine laboratory monitoring (control group). The study's primary endpoint was the overall impact of routine laboratory monitoring. The secondary endpoints were evaluation of patients with complications. RESULTS: The population in the two groups were similar in term of demographic and intra-operative data. There was a statistical difference between the two groups in term of length of stay (5.7 days in the LAB group and 3.5 days in the control group (p < 0.001)). There were 19 complications (6.0%) in the LAB group and 5 complications in the control group (3.5%) (p = 0.25). A cut-off C-reactive protein level of 46.3 mg/l was found to be significant (p = 0.006). In the LAB group, 9 patients (2.9%) required readmission vs. three patients (2.0%) in the control group (p = 0.62). CONCLUSION: The interest of routine laboratory monitoring after SG seems limited. Routine laboratory monitoring alone is not associated with earlier diagnosis of complications. This routine monitoring is associated with an increase of stay in hospital.

Breast cancer risk for the joint exposure to metals and metalloids in women: Results from the EPIC-Spain cohort.

Environmental factors play a role in breast cancer development. While metals and metalloids (MMs) include some carcinogens, their association with breast cancer depends on the element studied. Most studies focus on individual MMs, but the combined effects of metal mixtures remain unclear. The aim of this study was to analyze the relationship between the joint exposure to MMs and the risk of developing female breast cancer. We conducted a case-control study within the multicenter prospective EPIC-Spain cohort. Study population comprised 292 incident cases and 286 controls. Plasma concentrations of 16 MMs were quantified at recruitment. Potential confounders were collected using a questionnaire and anthropometric measurements. Mixed-effects logistic regression models were built to explore the effect of individual MMs. Quantile-based g computation models were applied to identify the main mixture components and to estimate the joint effect of the metal mixture. The geometric means were highest for Cu (845.6 ng/ml) and Zn (604.8 ng/ml). Cases had significantly higher Cu concentrations (p = 0.010) and significantly lower Zn concentrations (p < 0.001). Cu (+0.42) and Mn (+0.13) showed the highest positive weights, whereas Zn (-0.61) and W (-0.16) showed the highest negative weights. The joint effect of the metal mixture was estimated at an OR = 4.51 (95%CI = 2.32-8.79), suggesting a dose-response relationship. No evidence of non-linearity or non-additivity was found. An unfavorable exposure profile, primarily characterized by high Cu and low Zn levels, could lead to a significant increase in the risk of developing female breast cancer. Further studies are warranted to confirm these findings.

Assessment of phthalate exposure at a fire site in Korean firefighters.

To determine phthalate exposure in 32 firefighters, the concentrations of urinary phthalate metabolites, immediately (exposure day) and three weeks (control day) after fire suppression, were compared. Mono-(2-ethyl-5-carboxypentyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-n-butyl phthalate (MBP), mono-n-benzyl phthalate (MBzP), and total phthalates (∑phthalates) levels, and creatinine-adjusted levels of MBP, MBzP, and ∑phthalates were significantly higher on exposure day than on control day. Phthalate concentration was significantly higher in firefighters who performed the fire extinguishing tasks (geometric mean [GM], 149.9 µg/L) than in those who performed other tasks (GM 70.8 µg/L) (p = .012). The GM concentration of firefighters who were active ≤ 50 m from the fire was 119.0 µg/L, and 37.6 µg/L for those who were > 50 m away (p = .012). The GM concentration was significantly different (p = .039) in firefighters with subjective symptoms after fire suppression (151.9 µg/L) compared to those without symptoms (81.6 µg/L). This study showed that firefighters were exposed to phthalate.

Oxidative stress in occupational exposure to styrene vapors and dangerous chemicals in the shipbuilding industry.

Introduction: In the shipbuilding industry, workers are exposed to a variety of dangerous chemicals, styrene being one of them. The International Agency for Research on Cancer classified styrene as a chemical belonging to group 2A, which means it is probably carcinogenic to humans. This study aimed at evaluating the oxidative stress effects due to occupational exposure to styrene and other chemicals. Materials and methods: Styrene urinary metabolites, such as mandelic acid and phenylglyoxylic acid, and the urinary biomarkers of oxidative stress, i.e., oxidation products of DNA and RNA and of proteins, were measured in a group of 17 workers and compared to the concentrations found in a group of 17 healthy volunteers who had not been exposed to chemicals. Results and discussion: Statistically significant differences were found for 8-oxo-7,8-dihydroguanine (8-oxoGua) and 8-oxo-7,8-dihydro-2'-deoxiguanosine (8-oxodGuo) concentrations that are higher in workers than in the control group. The workers performing the tasks of painting are the most exposed to styrene and show higher concentrations of 8-oxo-7,8-dihydroguanosine (8-oxoGuo). Workers performing the tasks of wood refining and welding are less exposed to styrene but have higher concentrations of 8-oxoGua and 8-oxodGuo. Conclusion: The exposure scenario in shipbuilding is a complex one, in which different xenobiotics are simultaneously present. The oxidative stress effect biomarkers, obtained from the oxidation product of RNA and DNA, are promising, sensitive, but not specific.

Environmental transcriptomics under heat stress: Can environmental RNA reveal changes in gene expression of aquatic organisms?

To safeguard biodiversity in a changing climate, taxonomic information about species turnover and insights into the health of organisms are required. Environmental DNA approaches are increasingly used for species identification, but cannot provide functional insights. Transcriptomic methods reveal the physiological states of macroorganisms, but are currently species-specific and require tissue sampling or animal sacrifice, making community-wide assessments challenging. Here, we test whether broad functional information (expression level of the transcribed genes) can be harnessed from environmental RNA (eRNA), which includes extra-organismal RNA from macroorganisms along with whole microorganisms. We exposed Daphnia pulex as well as phytoplankton prey and microorganism colonizers to control (20°C) and heat stress (28°C) conditions for 7 days. We sequenced eRNA from tank water (after complete removal of Daphnia) as well as RNA from Daphnia tissue, enabling comparisons of extra-organismal and organismal RNA-based gene expression profiles. Both RNA types detected similar heat stress responses of Daphnia. Using eRNA, we identified 32 Daphnia genes to be differentially expressed following heat stress. Of these, 17 were also differentially expressed and exhibited similar levels of relative expression in organismal RNA. In addition to the extra-organismal Daphnia response, eRNA detected community-wide heat stress responses consisting of distinct functional profiles and 121 differentially expressed genes across eight taxa. Our study demonstrates that environmental transcriptomics based on extra-organismal eRNA can noninvasively reveal gene expression responses of macroorganisms following environmental changes, with broad potential implications for the biomonitoring of health across the trophic chain.

A regional comparison of children's blood cadmium, lead, and mercury in rural, urban and industrial areas of six European countries, and China, Ecuador, and Morocco.

OBJECTIVES: The authors aimed to evaluate whether blood cadmium (B-Cd), lead (B-Pb) and mercury (B-Hg) in children differ regionally in 9 countries, and to identify factors correlating with exposure. MATERIAL AND METHODS: The authors performed a cross-sectional study of children aged 7-14 years, living in 2007-2008 in urban, rural, or potentially polluted ("hot spot") areas (ca. 50 children from each area, in total 1363 children) in 6 European and 3 non-European countries. The authors analyzed Cd, Pb, and total Hg in blood and collected information on potential determinants of exposure through questionnaires. Regional differences in exposure levels were assessed within each country. RESULTS: Children living near industrial "hot-spots" had B-Cd 1.6 (95% CI: 1.4-1.9) times higher in the Czech Republic and 2.1 (95% CI:1.6-2.8) times higher in Poland, as compared to urban children in the same countries (geometric means [GM]: 0.13 µg/l and 0.15 µg/l, respectively). Correspondingly, B-Pb in the "hot spot" areas was 1.8 (95% CI: 1.6-2.1) times higher than in urban areas in Slovakia and 2.3 (95% CI: 1.9-2.7) times higher in Poland (urban GM: 19.4 µg/l and 16.3 µg/l, respectively). In China and Morocco, rural children had significantly lower B-Pb than urban ones (urban GM: 64 µg/l and 71 µg/l, respectively), suggesting urban exposure from leaded petrol, water pipes and/or coal-burning. Hg "hot spot" areas in China had B-Hg 3.1 (95% CI: 2.7-3.5) times higher, and Ecuador 1.5 (95% CI: 1.2-1.9) times higher, as compared to urban areas (urban GM: 2.45 µg/l and 3.23 µg/l, respectively). Besides industrial exposure, traffic correlated with B-Cd; male sex, environmental tobacco smoke, and offal consumption with B-Pb; and fish consumption and amalgam fillings with B-Hg. However, these correlations could only marginally explain regional differences. CONCLUSIONS: These mainly European results indicate that some children experience about doubled exposures to toxic elements just because of where they live. These exposures are unsafe, identifiable, and preventable and therefore call for preventive actions. Int J Occup Med Environ Health. 2023;36(3):349-64.

[Research on Occupational Poisoning and Biological Monitoring].

OBJECTIVE: A new system for the regulation of chemical substances was introduced in Japan in April 2023. Unlike delineated rules, the new system does not specify any specific measures for individual substances, but is rather based on the management of health through the voluntary implementation of measures in order to reduce exposure to all dangerous/hazardous chemical substances. Regarding specific methods, exposures will be mainly elucidated through the measurement of a work environment. However, the necessity of biological monitoring should also be considered. This study aimed to identify the importance of biological monitoring by reviewing changes made over time in biological monitoring methods used for occupational poisoning. METHOD: The study presents occupational poisoning by several compounds (methyl bromide, polycyclic aromatic hydrocarbons, and MOCA) and the corresponding biological monitoring methods utilized, as researched by the author. Changes in biological monitoring based on the history of the Study Group on Occupational Poisoning and Biological Monitoring of the Japan Society for Occupational Health are also introduced. RESULTS: The areas of occupational poisoning at different times and cases of occupational cancer caused by exposure to chemical substances were presented in lectures held by the Study Group on Occupational Poisoning and Biological Monitoring. These lectures showed that although biological monitoring was previously implemented primarily by measuring the urinary metabolites of the exposed substance, the monitoring methods used have changed as the nature of exposure has changed, leading to the development of new tools that detect trace, low concentration, and mixed exposures. CONCLUSION: The health management of workers handling chemical substances at occupational sites will be shifted to autonomous management. However, it should be noted that only biological monitoring can detect and prove true exposure. Particularly, risk assessment by biological monitoring is necessary for substances that are suspected to be absorbed through the skin, and the measurement methods used should continue to be developed and refined. The significance of biological monitoring will continue to increase.

Environmental DNA metabarcoding serves as a promising method for aquatic species monitoring and management: A review focused on its workflow, applications, challenges and prospects.

Marine and freshwater biodiversity is under threat from both natural and manmade causes. Biological monitoring is currently a top priority for biodiversity protection. Given present limitations, traditional biological monitoring methods may not achieve the proposed monitoring aims. Environmental DNA metabarcoding technology reflects species information by capturing and extracting DNA from environmental samples, using molecular biology techniques to sequence and analyze the DNA, and comparing the obtained information with existing reference libraries to obtain species identification. However, its practical application has highlighted several limitations. This paper summarizes the main steps in the environmental application of eDNA metabarcoding technology in aquatic ecosystems, including the discovery of unknown species, the detection of invasive species, and evaluations of biodiversity. At present, with the rapid development of big data and artificial intelligence, certain advanced technologies and devices can be combined with environmental DNA metabarcoding technology to promote further development of aquatic species monitoring and management.

Environmental RNA as a Noninvasive Tool for Assessing Toxic Effects in Fish: A Proof-of-concept Study Using Japanese Medaka Exposed to Pyrene.

Although environmental RNA (eRNA) is emerging as a noninvasive tool to assess the health status of aquatic macroorganisms, the potential of eRNA in assessing chemical hazards remain largely untested. In this study, we investigated the ability of eRNA to detect changes in gene expression in Japanese medaka fish (Oryzias latipes) in response to sublethal pyrene exposure, as a model toxic chemical. We performed standardized acute toxicity tests and collected eRNA from tank water and RNA from fish tissue after 96 h of exposure. Our results showed that over 1000 genes were detected in eRNA and the sequenced read counts of these genes correlated with those in fish tissue (r = 0.50). Moreover, eRNA detected 86 differentially expressed genes in response to pyrene, some of which were shared by fish RNA, including the suppression of collagen fiber genes. These results suggest that eRNA has the potential to detect changes in gene expression in fish in response to environmental stressors without the need for sacrificing or causing pain to fish. However, we also found that the majority of sequenced reads of eRNA (>99%) were not mapped to the reference medaka genome and they originated from bacteria and fungi, resulting in low sequencing depth. In addition, eRNA, in particular nuclear genes, was highly degraded with a median transcript integrity number (TIN) of <20. These limitations highlight the need for future studies to improve the analytical methods of eRNA application.

Human biomonitoring of deoxynivalenol (DON) - Assessment of the exposure of young German adults from 1996 - 2021.

The mycotoxin deoxynivalenol (DON) is a frequently found contaminant in cereals and cereal-based products. As a German contribution to the European Joint Programme HBM4EU, we analysed the total DON concentration (tDON) in 24-h urine samples from the German Environmental Specimen Bank (ESB). In total, 360 samples collected in 1996, 2001, 2006, 2011, 2016, and 2021 from young adults in Muenster (Germany), were measured by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) after enzymatic deconjugation of the glucuronide metabolites. tDON was found in concentrations above the lower limit of quantification (0.3 µg/L) in 99% of the samples. Medians of the measured concentrations and the daily excretion were 4.3 µg/L and 7.9 µg/24 h, respectively. For only nine participants, urinary tDON concentrations exceeded the provisional Human biomonitoring guidance value (HBM GV) of 23 µg/L. Urinary tDON concentrations were significantly higher for male participants. However, 24-h excretion values normalized to the participant's body weight did not exhibit any significant difference between males and females and the magnitude remained unchanged over the sampling years with exception of the sampling year 2001. Daily intakes were estimated from excretion values. Exceedance of the tolerable daily intake (TDI) of 1 µg/kg bw per day was observed for less than 1% of all participants. TDI exceedances were only present in the sampling year 2001 and not in more recent sampling years while exceedance of the HBM guidance value was also observed in 2011 and 2021.

Research progress in human biological monitoring of aromatic hydrocarbon with emphasis on the analytical technology of biomarkers.

Aromatic hydrocarbons are unsaturated compounds containing carbon and hydrogen that form single aromatic ring, or double, triple, or multiple fused rings. This review focuses on the research progress of aromatic hydrocarbons represented by polycyclic aromatic hydrocarbons (including halogenated polycyclic aromatic hydrocarbons), benzene and its derivatives including toluene, ethylbenzene, xylenes (o-, m- and p-), styrene, nitrobenzene, and aniline. Due to the toxicity, widespread coexistence, and persistence of aromatic hydrocarbons in the environment, accurate assessment of exposure to aromatic hydrocarbons is essential to protect human health. The effects of aromatic hydrocarbons on human health are mainly derived from three aspects: different routes of exposure, the duration and relative toxicity of aromatic hydrocarbons, and the concentration of aromatic hydrocarbons which should be below the biological exposure limit. Therefore, this review discusses the primary exposure routes, toxic effects on humans, and key populations, in particular. This review briefly summarizes the different biomarker indicators of main aromatic hydrocarbons in urine, since most aromatic hydrocarbon metabolites are excreted via urine, which is more feasible, convenient, and non-invasive. In this review, the pretreatment and analytical techniques are compiled systematically for the qualitative and quantitative assessments of aromatic hydrocarbons metabolites such as gas chromatography and high-performance liquid chromatography with multiple detectors. This review aims to identify and monitor the co-exposure of aromatic hydrocarbons that provides a basis for the formulation of corresponding health risk control measures and guide the adjustment of the exposure dose of pollutants to the population.

Alterations to biomarkers related to long-term exposure to diesel exhaust at concentrations below occupational exposure limits in the European Union and the USA.

BACKGROUND: We previously found that occupational exposure to diesel engine exhaust (DEE) was associated with alterations to 19 biomarkers that potentially reflect the mechanisms of carcinogenesis. Whether DEE is associated with biological alterations at concentrations under existing or recommended occupational exposure limits (OELs) is unclear. METHODS: In a cross-sectional study of 54 factory workers exposed long-term to DEE and 55 unexposed controls, we reanalysed the 19 previously identified biomarkers. Multivariable linear regression was used to compare biomarker levels between DEE-exposed versus unexposed subjects and to assess elemental carbon (EC) exposure-response relationships, adjusted for age and smoking status. We analysed each biomarker at EC concentrations below the US Mine Safety and Health Administration (MSHA) OEL (<106 µg/m3), below the European Union (EU) OEL (<50 µg/m3) and below the American Conference of Governmental Industrial Hygienists (ACGIH) recommendation (<20 µg/m3). RESULTS: Below the MSHA OEL, 17 biomarkers were altered between DEE-exposed workers and unexposed controls. Below the EU OEL, DEE-exposed workers had elevated lymphocytes (p=9E-03, false discovery rate (FDR)=0.04), CD4+ count (p=0.02, FDR=0.05), CD8+ count (p=5E-03, FDR=0.03) and miR-92a-3p (p=0.02, FDR=0.05), and nasal turbinate gene expression (first principal component: p=1E-06, FDR=2E-05), as well as decreased C-reactive protein (p=0.02, FDR=0.05), macrophage inflammatory protein-1ß (p=0.04, FDR=0.09), miR-423-3p (p=0.04, FDR=0.09) and miR-122-5p (p=2E-03, FDR=0.02). Even at EC concentrations under the ACGIH recommendation, we found some evidence of exposure-response relationships for miR-423-3p (ptrend=0.01, FDR=0.19) and gene expression (ptrend=0.02, FDR=0.19). CONCLUSIONS: DEE exposure under existing or recommended OELs may be associated with biomarkers reflective of cancer-related processes, including inflammatory/immune response.

Occupational Exposure to Metal Engineered Nanoparticles: A Human Biomonitoring Pilot Study Involving Italian Nanomaterial Workers.

Advances in nanotechnology have led to an increased use of engineered nanoparticles (ENPs) and the likelihood for occupational exposures. However, how to assess such exposure remains a challenge. In this study, a methodology for human biomonitoring, based on Single Particle Inductively Coupled Plasma Mass Spectrometry (SP-ICP-MS), was developed as a tool to assess the ENPs exposure of workers involved in nanomaterial activities in two Italian Companies. The method was validated for size and number concentration determination of Ag, Au, In2O3, Ir, Pd, Pt, and TiO2 NPs in urine and blood samples. The results showed the presence of In2O3 NPs in blood of exposed workers (mean, 38 nm and 10,371 particles/mL), but not in blood of controls. Silver, Au, and TiO2 NPs were found in urine (mean, Ag 29 nm and 16,568 particles/mL) or blood (mean, Au 15 nm and 126,635 particles/mL; TiO2 84 nm and 27,705 particles/mL) of workers, though these NPs were found also in controls. The presence of ENPs in both workers and controls suggested that the extra-professional exposure is a source of ENPs that cannot be disregarded. Iridium, Pd, and Pt NPs were not detected neither in blood nor in urine. Overall, the findings provided a rational basis to evaluate the exposure assessment to ENPs in cohorts of workers as part of risk assessment and risk management processes in workplaces.

Biological monitoring and personal exposure to traffic-related air pollutants of elementary school-age children living in a metropolitan area.

An ever-growing burden of scientific evidence links air pollution to different aspects of human health even at very low concentrations; the impact increases for those living in urban environments, especially the youngest and the elderly. This study investigated the exposure to air pollution of urban school children of Milan, Italy, by personal and biological monitoring, in the frame of the MAPS-MI project. A total of 128 primary school children (7-11 years) were involved in a two-season monitoring campaign during spring 2018 and winter 2019. Personal exposure to airborne VOCs and eBC, and biological monitoring of urinary benzene (BEN-U) and methyl-tert-butyl ether (MTBE-U) were performed. Time-activity patterns, environmental tobacco smoke (ETS), spatial, and meteorological information were evaluated as determinants in mixed effects regression analysis. Children personal exposure was mostly quantifiable with median (5th-95th percentile) levels 1.9 (0.8-7.5) µg/m3 for eBC, and 1.1 (<0.6-3.4) and 0.8 (0.3-1.8) µg/m3 for benzene and MTBE, respectively; with values 2-3-fold higher in winter than in spring. In urine, median (5th-95th) BEN-U and MTBE-U levels were 44.9 (25.7-98.6) and 11.5 (5.0-35.5) ng/L, respectively. Mixed effect regression models explained from 72 to 93 % of the total variability for air pollutants, and from 58 to 61 % for biomarkers. Major contributors of personal exposure were season, wind speed, mobility- or traffic-related variables; biomarkers were mostly predicted by airborne exposure and ETS. Our results suggest that traffic-mitigation actions, together with parents' educational interventions on ETS and commuting mode, should be undertaken to lower children exposure to air pollution.

Urinary concentrations of metals before and after volcanic eruption: a natural experiment surrounding the eruption of Volcán de Fuego, 2018.

Volcanic eruptions increase environmental heavy metal concentrations, yet little research has been performed on their extrapulmonary human health effects. We fortuitously collected biological samples in a cohort of Guatemalan sugarcane cutters in the area surrounding Volcán de Fuego before and after the June 2018 eruption. We sought to determine whether stratovolcanic activity was associated with changes in urinary concentrations of heavy metals in a cohort of sugarcane workers. In this exploratory analysis, we found significant increases in urinary arsenic, (ß = 1.46, P < 0.0001), cadmium (ß = 1.03, P < 0.0001), and lead (ß = 0.87, P = 0.003) in participants with residential proximity to Volcán de Fuego as compared to participants farther away, suggesting that volcanic activity could be associated with acute heavy metal exposures. This natural experiment is, to our knowledge, the first of its kind and suggests a need for more research into heavy metal exposure-related health impacts of volcanic eruptions.