Precise Exposure Assessment Research Articles

Night shift work and breast cancer risk – 2023 update of epidemiologic evidence

IntroductionNight shift work is a complex and frequent occupational exposure, and breast cancer stands as the most prevalent cancer in women. The International Agency for Research on Cancer (IARC) has twice classified night shift work as a probable breast carcinogen, with the latest classification in June 2019. Since that time, new epidemiologic data has emerged. MethodsWe searched PubMed for original articles based on cohort and case- control studies of “breast cancer and night shift work” published after the IARC evaluation in June 2019. ResultsIn total six cohorts and four case-control studies were included in our review. Overall, we observed some support for associations between persistent (long duration or high frequency) night shift work and an increase in breast cancer risk, though most studies were relatively small and statistically under-powered. Moreover, the recent studies do not contribute further evidence regarding the interaction with menopausal status, diurnal preference, hormonal subtypes of breast cancer or gene-environment aspects, which were issues that were left from the IARC evaluation. ConclusionThe available new results somewhat consolidate the epidemiological evidence from IARC's 2019 evaluation, and do not provide further evidence regarding interaction of interest, e.g. menopausal status, etc. Therefore, long term follow-up of prospective cohorts or nested case-control studies, including precise exposure assessment and examinations of relevant interactions such as menopausal status, diurnal preference, hormonal subtypes of breast cancer and gene-environment aspects, are warranted. Meanwhile, protective measures for the night workers should be considered.

Tracing semi-quantitatively the absorption and removal of organic pollutants in human hair based on secondary ion mass spectrometry

Human hair has become a promising non-invasive matrix in assessing exposure to environmental organic pollutants (OPs). However, exogenous contaminants, which were absorbed into the hair via sweat, sebum, and air particles/dust, could contribute to OP levels in hair and interfere with the precise exposure assessment. So far, the microscopic mechanisms underlying the absorption of exogenous OPs into hair remain inadequately understood. This study focused on the in-situ investigation of the diffusion processes of exogenous OPs into the hair structure using secondary ion mass spectrometry (SIMS) and isotopic tracer techniques. Results showed that the relative signal intensities of deuterium-labeled tris(1,3-dichloro-2-propyl) phosphate (TDCPP), 1-hydroxypyrene (1-OH-Pry), and bisphenol A (BPA) in the hair cortex were notably elevated after a 6-hour exposure. Diffusion coefficients of contaminants were related to their molecular weight, and absorption volumes to their water solubility and molecular structures. Exposure duration and solvent influenced the rate of diffusion and absorption volumes. The distribution of deuterium-labeled molecules in exposed hair samples after washing with two different solvents (acetone or water) was similar to that before washing. Our findings revealed the diffusion of OPs in hair cross-sections, indicating exogenous contributions to contaminants that are biologically incorporated into the hair.

Neurotoxicity from long-term exposure to 6-PPDQ: Recent advances

The recent acceleration of industrialization and urbanization has brought significant attention to N-(1,3-Dimethylbutyl)-N′-phenyl-p-phenylenediamine quinone (6-PPDQ), an emerging environmental pollutant from tire wear, due to its long-term effects on the environment and organisms. Recent studies suggest that 6-PPDQ can disrupt neurotransmitter synthesis and release, impact receptor function, and alter signaling pathways, potentially causing oxidative stress, inflammation, and apoptosis. This review investigates the potential neurotoxic effects of prolonged 6-PPDQ exposure, the mechanisms underlying its cytotoxicity, and the associated health risks. We emphasize the need for future research, including precise exposure assessments, identification of individual differences, and development of risk assessments and intervention strategies. This article provides a comprehensive overview of 6-PPDQ's behavior, impact, and neurotoxicity in the environment, highlighting key areas and challenges for future research.

Self-reported exposure to dust and diesel exhaust, respiratory symptoms, and use of respiratory protective equipment among Arctic miners

ABSTRACT Arctic miners face significant risks from diesel exhaust and dust exposure, potentially leading to adverse respiratory health. Employers must limit harmful exposures, using personal protective equipment (PPE) as a last line of defense. This study explored the association between reported respiratory exposure and symptoms, and PPE training and usage. Data from the MineHealth study (2012–2014) included a total of 453 Arctic open pit miners in Norway, Sweden, and Finland. Participants answered questions on exposure to dust and diesel exhaust, respiratory symptoms, and PPE use, in addition to age, gender, BMI, smoking, and self-rated health. Estimated exposure to dust was common, reported by 91%, 80%, and 82% and that of diesel exhaust by 84%, 43%, and 47% of workers in Sweden, Finland, and Norway, respectively. Reported dust exposure was significantly related to respiratory symptoms (OR 2.2, 95% CI 1.3–3.7), diesel exposure increased the occurrence of wheezing (OR 2.6, 95% CI 1.3–5.4). PPE use varied between the studied mines. Non-use was common and related to reduced visibility, wetness, skin irritation and fogging of the respiratory PPE. Future research should employ more precise exposure assessment, respiratory function as well as explore the reasons behind the non-compliance of PPE use.

A spatial approach to assessing PM2.5 exposure level of a brickmaking community in South Africa

ABSTRACT Globally, particulate matter with an aerodynamic diameter of 2.5 µm or less poses a significant threat to human health. The first step in quantifying human health impacts caused by exposure to PM2.5 pollution is exposure assessment. Population-weighted exposure level (PWEL) estimation is one of the methods that provides a more precise exposure assessment since it incorporates the spatiotemporal distribution of population with the pollution concentration estimate. In this study, PM2.5 exposure levels in the local communities around brickmaking industries were investigated, using the population census data of the study area and 1-year data from nine PM2.5 monitoring stations installed in and around the brickmaking industries. The observed PM2.5 data was spatially interpolated using inverse distance weight (IDW). Data on PM2.5 levels across the study area were classified based on the World Health Organization interim target (IT) guidelines and the South African National ambient air quality standard (NAAQS). An annual PM2.5 population weighted exposure level of 27.6 µg/m3 was estimated for the study area. However, seasonal exposure levels of 28.9, 37.6, 26.5, and 20.7 µg/m3 were estimated for the autumn, winter, spring, and summer seasons, respectively. This implies that local communities around the brick kiln in the Vhembe District are exposed to high levels of PM2.5, especially in winter. The PM2.5 levels in the brickmaking industries as well as its other sources in the Vhembe District, therefore, need to be lowered. Findings from population exposure level to pollutants can provide valuable data for formulating policies and recommendations on exposure reduction and public health protection. Implications: PM2.5 concentration in any given environment has high spatial and temporal variability due to the presence of diffused sources in the environment. Using ambient air concentrations to directly estimate population exposure without taking into consideration the disproportionate spatial and temporal distribution of the pollutant and the population may not yield accurate results on human exposure levels. It is, therefore, important to assess the aggregated PM2.5 exposure of a populace within a given area. This study therefore examines the PM2.5 population-weighted-exposure level of the host communities of the brickmaking industry in Vhembe District, South Africa.

Working hours and health - key research topics in the past and future.

This paper discusses the past and present highlights of working hours and health research and identifies key research needs for the future. We analyzed over 220 original articles and reviews on working hours and health in the Scandinavian Journal of Work, Environment & Health published during the last 50 years. Key publications from other journals were also included. The majority of identified articles focussed on the effects of shift and night work, with fewer studying long and reduced working hours and work time control. We observed a transition from small-scale experimental and intensive field studies to large-scale epidemiological studies utilizing precise exposure assessment, reflecting the recent emergence of register-based datasets and the development of analytic methods and alternative study designs for randomized controlled designs. The cumulative findings provide convincing evidence that shift work and long working hours, which are often associated with night work and insufficient recovery, increase the risk of poor sleep and fatigue, sickness absence, occupational injuries, and several chronic health conditions such as cardiovascular diseases and cancer. The observed risks are strongly modified by individual and work-related factors. Although the observed health risks of shift work and long working hours are mostly low or moderate, the widespread prevalence of exposure and the hazardousness of the many associated potential outcomes makes such working time arrangements major occupational health risks. Further research is needed to identify exposure-response associations, especially in relation to the chronic health effects, and to elucidate underlying pathways and effective personalized intervention strategies.

Exposure to outdoor artificial light at night and breast cancer risk: a population-based case-control study in two French departments (the CECILE study)

BackgroundExposure to outdoor artificial light at night (LAN) disrupts circadian rhythms and is suspected of increasing the risk of breast cancer. To date, this is an understudied aspect of environmental pollution. In this study, we sought to assess the specific role of exposure to outdoor artificial light at night in breast cancer, independently of air pollution-related effects.MethodsData from a French population-based case-control study, including 1,185 incident breast cancer cases and 1,282 controls enrolled in 2005–2007, were used. Outdoor LAN exposure data were obtained using radiance-calibrated images from the Defense Meteorological Satellite Program (DMSP) for 1995–2006 by cross-referencing the DMSP images and the geocoded locations of residences in ArcGIS. The odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were obtained using logistic regression adjusting for multiple potential confounders, including air pollution.ResultsThe OR for overall breast cancer unadjusted for air pollution per interquartile range increase in LAN exposure was 1.05 (95% CI: 0.92–1.20). The OR decreased to 0.98 (95% CI: 0.81–1.17) after adjustment for ambient NO2 levels. Subgroup analyses showed slightly higher ORs in postmenopausal women (OR per IQR increase: 1.07; 95% CI: 0.85–1.35) and a positive association for HER2-positive breast tumors (OR: 1.55; 95% CI: 1.03–2.31).ConclusionOur results do not provide evidence that outdoor LAN exposure is associated with increased risk of breast cancer. However, an association was suggested for the HER2-positive subtype of breast cancer. Further large-scale studies with more precise exposure assessment methods, including blue light and indoor exposure measurements, and considering environmental exposures correlated with LAN exposure such as air pollution, are needed.

The First Attempt to Reevaluate Radon and Thoron Exposure in Gansu Province Study Using Radon-Thoron Discriminating Measurement Technique.

Although the epidemiological studies provide evidence for an increased risk of lung cancer risk associated with residential radon, an issue of radon-thoron discrimination remains to be solved. In this study, an updated evaluation of lung cancer risk among the residents in Gansu, China was performed where one of the major epidemiological studies on indoor radon demonstrated an increased risk of lung cancer. We analyzed data from a hospital-based case-control study that included 30 lung cancer cases and 39 controls with special attention to internal exposure assessment based on the discriminative measurement technique of radon isotopes. Results from the analyses showed non-significant increased lung cancer risks; odds ratios (ORs) adjusted for age, smoking, and total income were 0.35 (95% CI: 0.07–1.74) and 0.27 (95% CI: 0.04–1.74) for groups living in residences with indoor radon concentrations of 50–100 Bq m−3 and over 100 Bq m−3, respectively, compared with those with < 50 Bq m−3 indoor radon concentrations. Although the small sample size hampers the usefulness of present analyses, our study suggests that reevaluation of lung cancer risk associated with residential radon in the epidemiological studies will be required on the basis of precise exposure assessment.

Untargeted Metabolomics Reveals that Multiple Reproductive Toxicants are Present in the Endometrium

BACKGROUND AND AIM: Recent epidemiological research focused on the effects of environmental chemicals on the female reproductive system shows mixed results, which may be partially due to differences in exposure assessment, residual confounding from diet or lifestyle factors, or co-exposures to other chemicals. These challenges highlight the need for more precise exposure assessment at the end-organ of interest to accurately understand the adverse reproductive effects of environmental exposures. Our aim was to perform untargeted metabolomic analysis of menstrual blood, a novel biospecimen, to identify environmental toxins present in the endometrium. METHODS: Whole menstrual effluent samples were collected from four women using a menstrual cup. To evaluate the effect of sample processing times, one portion of menstrual effluent was immediately frozen at -20°C for 24hrs and the second portion was kept at 4°C for 24hrs; both samples were then stored at -80°C. Samples were analyzed using untargeted liquid chromatography with high-resolution mass spectrometry (LC-HRMS). To survey the presence of environmental exposures, LC-HRMS chemical profiles were matched to the ToxCast chemical database, which includes 4,557 commonly used commercial chemicals. Select compounds were confirmed using MS/MS and comparison to reference standards. Principal component analysis (PCA) was used to identify differences within and between individuals’ menstrual blood metabolomic profiles, and the influence of the sample processing method. RESULTS:We identified 261 high confidence matches to environmental chemicals, including suspected reproductive toxicants such as phenols, parabens, phthalates, and organochlorides. PCA showed analysis of menstrual blood samples was highly reproducible, with much higher variability between participants than between an individual’s analytical replicates. CONCLUSIONS:Our results show chemical exposures linked to reproductive toxicity and endocrine disruption are present in the endometrium. In addition, our results demonstrate that menstrual blood can be successfully collected and provides a suitable biofluid for untargeted profiling to assess environmental exposures associated with potential adverse reproductive outcomes. KEYWORDS: metabolomics, exposome, biomarkers of exposure, endocrine disrupting chemicals, reproductive outcomes

Traffic-Related Air Pollution: A Moving Target

BACKGROUND AND AIM: Traffic-related air pollution (TRAP) is variable on multiple and spatial and temporal scales. It’s chemical and physical characteristics represent additional, highly variable dimensions and thus TRAP is described as a complex mixture. This presentation will explore this complexity, highlighting implications for exposure and epidemiological research for informing, understanding and reducing its health effects. METHODS: Real-world measurements of TRAP, focusing on near-road and mobile platforms, were analyzed and interpreted. Examples of changing mixture characteristics and changing patterns in inter-pollutant correlations were identified and compared. Changes having implications for precise exposure assessment and subsequent epidemiological analyses as well as interpretation of heterogeneity among studies were of particular interest. RESULTS:Nitrogen dioxide (NO2) has been a common indicator of TRAP and black carbon (EC or BC) has been of interest as a TRAP-related sub-component of fine particles (PM2.5). Ultrafine particles (UFP) represent another dimension of TRAP and of PM2.5, which is less-specific to TRAP, due to less urban-scale variability. Measurements from the tailpipe to the urban background show that while each of these are linked to TRAP their interrelations are inconsistent and also highlight the complexity of the mixture in terms infrequently measured components (e.g., metals, VOCs, toxics). Secondary products of traffic emissions contributing to urban exposures are potentially underappreciated given the challenge of characterizing their behavior independent of the urban background. CONCLUSIONS:Characterizing TRAP exposure for epidemiological research uncovering the level of risk attributed to motor vehicle contributions to air pollution has been reasonably-well served through the use of certain indicators. However, the common indicators (e.g., NO2) are less able to advance understanding into ongoing critical questions such as what components in the mixture, including secondary products, should be prioritized for control or whether current and/or future decreasing trends in NO2 translate into the benefits past epidemiological studies suggest. KEYWORDS: Air Pollution, Exposures, Traffic-Related

Retraction Note: Exposure Assessment for Roller Compacted Concrete Dam Construction Integrated Real-Time Location Information

Roller compacted concrete (RCC) dam projects are generally initiated in dynamic environment, where space conflicts occur frequently. Construction workers are often exposed to dangers posed by activities performed by teams other than their own. Therefore, it’s critical for construction security to conduct fairly precise exposure assessment. Several research studies have been proposed to address this site safety issue. Despite their valuable contributions, few of them have noticed that, for some construction processes, their hazard scope may exceed the work space. Another limitation is that most traditional methods expound space factor and time factor separately rather than comprehensively. Accordingly, the present paper proposes a novel method to quantify exposure frequency integrated with the real-time location information of three-dimensional cross activities. Combined with the construction process cycle and the operation time characteristics, conflicts between impact space and work space are determined in real time, which is more accurate as the interaction between construction activities is certain at each moment. With a reliable assessment of hazard exposure levels, construction managers will be able to provide solutions to reduce hazards to acceptable levels.

Harmful Effects of Ambient Nitrogen Dioxide on Atopic Dermatitis: Comparison of Exposure Assessment Based on Monitored Concentrations and Modeled Estimates

Precise exposure assessment of air pollutants is crucial in epidemiologic studies to ensure valid estimates of health effects. We conducted a longitudinal study to evaluate the role of air quality monitoring (AQM) measurements and high-resolution modeling outcomes focusing on nitrogen dioxide (NO2) exposure and atopic dermatitis (AD). A total of 128 young children with AD in Seoul Metropolitan Area, Korea, were recruited as a panel. We estimated the participants’ exposure to NO2 for four months, from 1 April through 31 July 2014 based on (1) monitored levels from 60 AQM stations located at varying distances from residential areas (AQM station-based NO2, AQM-NO2) and (2) estimates from a community multi-scale air quality (CMAQ) modeling system with a high-resolution (1 × 1 km) (CMAQ-NO2). We then compared the effect of AQM-NO2 on AD symptoms with that of CMAQ-NO2. The average distance between the participants’ residences and the nearest AQM station was 2.03 ± 1.06 km, ranging from 0.28 km to 5.73 km. Based on AQM-NO2, the AD symptoms increased by 10.28% (95% confidence interval (CI): 3.24, 17.79) with an increase of 10 ppb of NO2. The effect estimates of CMAQ-NO2 were similar to those of AQM-NO2 when assessed in patients living within 3 km from the nearest AQM station. Even within 1 km, the CI estimate obtained from the CMAQ was much narrower than from AQM (44.18–49.54 vs. 7.02–64.75). However, the association of AQM-NO2 with AD symptoms of patients living beyond 3 km was not positive, whereas that of CMAQ-NO2 maintained positive. In conclusion, exposure to ambient NO2 is significantly associated with aggravation of AD symptoms in young children. In addition, our study suggests that exposure assessment of NO2 using measurement data obtained from monitoring stations far from residential locations can lead to misclassification bias.

RETRACTED ARTICLE: Exposure Assessment for Roller Compacted Concrete Dam Construction Integrated Real-Time Location Information

Roller compacted concrete (RCC) dam projects are generally initiated in dynamic environment, where space conflicts occur frequently. Construction workers are often exposed to dangers posed by activities performed by teams other than their own. Therefore, it's critical for construction security to conduct fairly precise exposure assessment. Several research studies have been proposed to address this site safety issue. Despite their valuable contributions, few of them have noticed that, for some construction processes, their hazard scope may exceed the work space. Another limitation is that most traditional methods expound space factor and time factor separately rather than comprehensively. Accordingly, the present paper proposes a novel method to quantify exposure frequency integrated with the real-time location information of three-dimensional cross activities. Combined with the construction process cycle and the operation time characteristics, conflicts between impact space and work space are determined in real time, which is more accurate as the interaction between construction activities is certain at each moment. With a reliable assessment of hazard exposure levels, construction managers will be able to provide solutions to reduce hazards to acceptable levels.

Precise exposure assessment revealed the cancer risk and disease burden caused by trihalomethanes and haloacetic acids in Shanghai indoor swimming pool water

Swimming pool disinfection byproducts (DBPs) are becoming increasingly common worldwide. Precise exposure and health risk assessment for DBPs in swimming pool water with optimized parameters for local and specific population is more urgently needed. This study aimed to determine the levels of trihalomethanes (THMs) and haloacetic acids (HAAs) in 16 public indoor swimming pools in Shanghai, China. Swimming habits were also investigated to obtain more accurate exposure assessment parameters. Precise exposure assessment through multiple pathways, resulting cancer risk, and disability-adjusted life years (DALYs) were assessed. Results indicated that the highest total level of THMs and HAAs occurred in autumn. The surveyed swimmers 9–17 years of age had higher average daily dose (ADD) of DBPs than swimmers ≥18 years of age. The total lifetime cancer risk (LCR) attributable to THMs and HAAs exceeded 10−6, which represents a negligible risk level (NRL). The cancer risk from inhalation exposure predominantly by THMs contributed more than 99% of the total risk. Annual disease burden was 19.0 person-years attributed to exposure of DBPs in swimming pool water in Shanghai. This study provides a paradigm and strategic reference of precise exposure assessments, risk assessments, and disease burden estimation of hazards in swimming pool water for other regions.

Residential proximity to roadways and placental-associated stillbirth: a case–control study

ABSTRACT We conducted a retrospective case–control study of 1,097 women in Massachusetts and Rhode Island, USA, to examine the association between stillbirth related to placental abruption or placental insufficiency and maternal exposure to traffic-related air pollution. We utilized distance to nearest roadway proximity metrics as a proxy for traffic-related air pollution exposure. No meaningful increase in the overall odds of placental-associated stillbirths was observed (adjusted OR: 1.1, 95% CI: 0.5–2.8). However, mothers living within 50 m of a roadway had a 60% increased odds of experiencing a stillbirth related to placental abruption compared to mothers living greater than 200 m away. This suggestive finding was imprecise due to the small case number in the highest exposure category (95% CI: 0.6–4.0). Future studies of placental abruption with more precise exposure assessments are warranted.

Residential Proximity to Roadways and Placenta-Associated Stillbirth: A Case-Control Study

Previous studies suggest that risk of stillbirth is elevated by maternal exposure to air pollution. We conducted a retrospective case-control study of 1,097 women to examine the association between stillbirth related to placental abruption or placental insufficiency and maternal exposure to traffic related air pollution. We utilized distance to nearest roadway proximity metrics as a proxy for traffic-related air pollution exposure. No meaningful increase in the overall odds of placental-associated stillbirths was observed (adjusted OR: 1.1, 95% CI: 0.5-2.8). However, mothers living within 50 meters of a roadway had a 60% increased odds of experiencing a stillbirth related to placental abruption compared to mothers living greater than 200 meters away, This suggestive finding was imprecise due to the small case number in the highest exposure category (95% CI 0.6-4.0). Future studies of placental abruption with more precise exposure assessments are warranted.

Review on Ultrafine Particle Health Effects

Background: Due to their small size, inhaled ultrafine particles (UFPs) may enter into alveoli and are even capable of penetrating cell membranes. Toxicological studies suggest that UFPs contribute to the development and progression of various diseases. However, epidemiological evidence for health effects of UFPs is scarce. The aim of this project is to give an overview of the epidemiological literature on the effects of UFPs on health.Methods: We conducted a systematic literature review searching MEDLINE and LUDOK data bases (time period January 2011 - May 2017) as well as a by hand search for review articles and conference proceedings. We focused on epidemiologic studies that investigated health effects of UFPs, included quantitative effect measures and had a common UFPs-measure. Data extraction and quality assessment using standard instruments was conducted by two reviewers.Results: Overall, 85 unique references were included in the review. Most of these studies were conducted in North America (n&amp;#61;37) or Western Europe (n&amp;#61;27). The majority of the studies investigated short-term effects (n&amp;#61;75). Ten studies investigated long-term associations. Short-term studies were dominated by panel studies with repeated measures, scripted exposure studies and time-series studies. The investigation of health effects in epidemiological studies has substantially developed during the last 7 years. Specifically, the more recent studies have undertaken efforts to control for co-pollutants in order to identify independent effects of UFPs. Despite the advances in the field, the evidence on health effects remains inconclusive or insufficient for most of the studied outcomes.Conclusions: A future challenge is the development of enhanced spatiotemporal models that are able to contribute to a more precise exposure assessment across larger areas and incorporate multipollutant models to estimate independent UFP effects.

Chronic exposure to traffic-related air pollution and cancer incidence among 10,000 patients undergoing percutaneous coronary interventions: A historical prospective study.

Background Exposure to traffic-related air pollution (TRAP) is considered to have a carcinogenic effect. The authors previously reported a nonsignificant association between TRAP and cancer risk in a relatively small cohort of myocardial infarction survivors. This study assessed whether TRAP exposure is associated with subsequent cancer in a large cohort of coronary patients. Methods & results Consecutive patients undergoing percutaneous coronary interventions in a major medical centre in central Israel from 2004 to 2014 were followed for cancer through 2015. Residential levels of nitrogen oxides (NOx) - a proxy for TRAP - were estimated based on a high-resolution national land use regression model. Cox proportional hazards models were constructed to study relationships with cancer. Among 12,784 candidate patients, 9816 had available exposure data and no history of cancer (mean age, 68 years; 77% men). During a median (25th-75th percentiles) follow-up of 7.0 (3.9-9.3) years, 773 incident cases of cancer (8%) were diagnosed. In a multivariable-adjusted model, a 10-ppb increase in mean NOx exposure was associated with hazard ratios (HRs) of 1.07 (95% confidence interval [CI] 1.00-1.15) for all-site cancer and 1.16 (95% CI 1.05-1.28) for cancers previously linked to TRAP (lung, breast, prostate, kidney and bladder). A stronger association was observed for breast cancer (HR = 1.43; 95% CI 1.12-1.83). Associations were slightly strengthened after limiting the cohort to patients with more precise exposure assessment. Conclusion Coronary patients exposed to TRAP are at increased risk of several types of cancer, particularly lung, prostate and breast. As these cancers are amenable to prevention strategies, identifying highly exposed patients may provide an opportunity to improve clinical care.

Challenges in risk assessment of multiple mycotoxins in food

Most fungi are able to produce several mycotoxins simultaneously and, consequently, to contaminate a wide variety of foodstuffs. Therefore, the risk of human co-exposure to multiple mycotoxins is real, raising a growing concern about their potential impact on human health. Besides, government and industry regulations are usually based on individual toxicities, and do not take into account the complex dynamics associated with interactions between co-occurring groups of mycotoxins. The present work assembles, for the first time, the challenges posed by the likelihood of human co-exposure to these toxins and the possibility of interactive effects occurring after absorption, towards knowledge generation to support a more accurate human risk assessment. Regarding hazard assessment, a physiologically-based framework is proposed in order to infer the health effects from exposure to multiple mycotoxins in food, including knowledge on the bioaccessibility, toxicokinetics and toxicodynamics of single and combined toxins. The prioritisation of the most relevant mixtures to be tested under experimental conditions that attempt to mimic human exposure and the use of adequate mathematical approaches to evaluate interactions, particularly concerning the combined genotoxicity, were identified as the main challenges for hazard assessment. Regarding exposure assessment, the need of harmonised food consumption data, availability of multianalyte methods for mycotoxin quantification, management of left-censored data, use of probabilistic models and multibiomarker approaches are highlighted, in order to develop a more precise and realistic exposure assessment. To conclude, further studies on hazard and exposure assessment of multiple mycotoxins, using harmonised methodologies, are crucial towards an improvement of data quality and a more reliable and robust risk characterisation, which is central for risk management and, consequently, to prevent mycotoxins-associated adverse effects. A deep understanding of the nature of interactions between multiple mycotoxins will contribute to draw real conclusions on the health impact of human exposure to mycotoxin mixtures.

Exposure to ambient air pollution-does it affect semen quality and the level of reproductive hormones?

Background: Ambient air pollution has been associated with a variety of reproductive disorders. However, a limited amount of research has been conducted to examine the association between air pollution and male reproductive outcomes, specifically semen quality.Aim: The present study was designed to address the hypothesis that exposure to fluctuating levels of specific air pollutants adversely affects sperm parameters and the level of reproductive hormones.Subjects and methods: The study population consisted of 327 men who were attending an infertility clinic in Łodź, Poland for diagnostic purposes and who had normal semen concentration of 15–300 mln/ml. All participants were interviewed and provided a semen sample. Air quality data were obtained from AirBase database.Results: The statistically significant association was observed between abnormalities in sperm morphology and exposure to all examined air pollutants (PM10, PM2.5, SO2, NOX, CO). Exposure to air pollutants (PM10, PM2.5, CO, NOx) was also negatively associated with the level of testosterone. Additional exposure to PM2.5, PM10 increase the percentage of cells with immature chromatin (HDS).Conclusions: The present study provides suggestive evidence of an association between ambient air pollution and sperm quality. Further research is needed to explore this association in more detail. Individual precise exposure assessment would be needed for more detailed risk characterization.