Monitoring Of Exposure Research Articles

Modern universal standardised trends in worker and public exposure monitoring and control in 21st century by Sohrabi URPS-based hypothesis

Abstract The Universal Radiation Protection System (URPS) was recently hypothesised by Sohrabi in order to address the many deficiencies of current radiation protection system. The ICRP system is currently practiced worldwide based on the linear no-threshold (LNT) model with no supporting health risk data at low effective doses. The ICRP only considers worker occupational doses and sets dose limits only on one portion of doses a worker or public receives. The URPS hypothesis equals human heath-effect risks per unit dose either from natural or man-made sources; formulates dose limits on all integrated doses an individual receives; considers worker also a member of public; conserves ‘cause-effect principle’ for epidemiology risk estimation; introduces dose fractionation concept in radiation protection; introduces the ‘URPS Model’ for bridging LNT, hormesis and threshold models; recommends establishing ‘National Patient Dose Registering System’; and defines modified/new exposure terms and definitions commensurate with URPS hypothesis, as advanced since 2014.

Cumulative dose sensing of malathion using a biocatalytic liquid crystal elastomer with chemical memory

The development of deployable biosensors that monitor the cumulative dose of toxic pesticides is essential to enable monitoring of soil and water exposure in populated areas. Liquid crystal elastomers (LCEs) offer unique potential as cumulative dose biosensors due to their ability to store chemical information within the polymer network that can later be decoded in the form of quantifiable shape changes. Here, we present an LCE-based biosensor for the detection of the organophosphorus pesticide malathion through the immobilization of the hydrolytic enzyme pig liver esterase (PLE). Exposure to malathion was detected via shape change of the LCE from a flat ribbon to a helical structure. Quantification of the helical pitch provided a label free readout that correlated directly with the cumulative dose of malathion and enabled detection of successive doses independent of dosage timing or dilution. The cumulative dose was chemically encoded in the LCE and could be decoded by hydration, even after successive drying and rehydration steps. Importantly, the signal from the LCE was largely insensitive to sensing conditions and to interference from various chemicals. The combined results illustrate the utility of biocatalytic LCEs for monitoring harmful pollutants while allowing continuous and cumulative dose sensing in real-world conditions.

Mitigating the impact of bisphenol A exposure on mortality: Is diet the key? A cohort study based on NHANES

Bisphenol A (BPA) is a widespread environmental pollutant linked to detrimental effects on human health and reduced life expectancy following chronic exposure. This prospective cohort study aimed to examine the association between BPA exposure and mortality in American adults and to explore the potential mitigating effects of dietary quality on BPA-related mortality. This study utilized data from 8761 American adults in the 2003–2016 National Health and Nutrition Examination Survey (NHANES). Urinary BPA levels were employed to assess BPA exposure, and dietary quality was evaluated using the Healthy Eating Index-2015 (HEI-2015). All-cause, cardiovascular disease (CVD), and cancer mortality statuses were determined until December 31, 2019, resulting in a cumulative follow-up of 80,564 person-years. The results showed that the highest tertile of urinary BPA levels corresponded to a 36% increase in all-cause mortality and a 62% increase in CVD mortality compared to the lowest tertile. In contrast, the highest tertile of HEI-2015 scores was associated with a 29% reduction in all-cause mortality relative to the lowest tertile. Although no significant interaction was found between HEI-2015 scores and urinary BPA levels concerning mortality, the association between HEI-2015 scores and both all-cause and CVD mortality was statistically significant at low urinary BPA levels. Continuous monitoring of BPA exposure is crucial for evaluating its long-term adverse health effects. Improving dietary quality can lower all-cause mortality and decrease the risk of all-cause and CVD mortality at low BPA exposure levels. However, due to the limited protective effect of dietary quality against BPA exposure, minimizing BPA exposure remains a vital goal.

An Overview to Molecularly Imprinted Electrochemical Sensors for the Detection of Bisphenol A.

Bisphenol A (BPA) is an industrial chemical used extensively in plastics and resins. However, its endocrine-disrupting properties pose risks to human health and the environment. Thus, accurate and rapid detection of BPA is crucial for exposure monitoring and risk mitigation. Molecularly imprinted electrochemical sensors (MIES) have emerged as a promising tool for BPA detection due to their high selectivity, sensitivity, affordability, and portability. This review provides a comprehensive overview of recent advances in MIES for BPA detection. We discuss the operating principles, fabrication strategies, materials, and methods used in MIES. Key findings show that MIES demonstrate detection limits comparable or superior to conventional methods like HPLC and GC-MS. Selectivity studies reveal excellent discrimination between BPA and structural analogs. Recent innovations in nanomaterials, novel monomers, and fabrication techniques have enhanced sensitivity, selectivity, and stability. However, limitations exist in reproducibility, selectivity, and stability. While challenges remain, MIES provide a low-cost portable detection method suitable for on-site BPA monitoring in diverse sectors. Further optimization of sensor fabrication and characterization will enable the immense potential of MIES for field-based BPA detection.

Pathologic Findings in Severe Coal Workers' Pneumoconiosis in Contemporary US Coal Miners.

The pathology of coal workers' pneumoconiosis (CWP) and its most severe form-progressive massive fibrosis (PMF)-in US coal miners has changed in recent years. Severe disease is occurring in younger miners and has been linked to an increase in silica dust exposure. To update the description of the pathologic features of CWP in contemporary miners compared to historical miners. This study is a retrospective expert classification of lung tissue from 85 historical and contemporary coal miners with PMF. Significant pathologic features were scored by using a standardized instrument with consensus achieved for major findings, including newly defined categories of PMF as coal-type, mixed-type, and silica-type. Pathologic features associated with silica dust exposure, including silica-type PMF, mineral dust alveolar proteinosis (MDAP), and immature (early stage) silicotic nodules, were increased in contemporary miners. Detailed descriptions of the pathology of contemporary CWP with illustrative figures are provided. Silica-related pathologies are more common in contemporary miners. Severe forms of CWP can be detected by subtyping PMF lesions (if present) or by identification of mature and immature silicotic nodules, coal mine dust-related alveolar proteinosis, and severe inflammation in coal miners' lungs. Silica-type PMF cases showed significantly higher levels of MDAP than either mixed- or coal-type PMF (P < .001). High profusion of birefringent silica/silicate particles was observed more frequently in cases with immature (early stage) silicotic nodules (P = .04). Severe inflammation was also significantly increased in contemporary miners (P = .03). Our findings underscore the urgent need to revise current exposure limits and monitoring of respirable crystalline silica in US coal mines.

Long-term monitoring of indoor, outdoor, and personal exposure to gaseous chemical compounds

Seasonal variations of chemical compounds in indoor air and outdoor air and personal exposure to these chemicals were continuously monitored for 6 years using four types of passive sampling devices: PSD-BPE/DNPH packed with 2,4-dinitrophenylhydrazine and trans-1,2-bis(2-pyridyl)ethylene coated silica for ozone and carbonyls; PSD-VOC packed with Carboxen 572 or Active Carbon Beads particles for volatile organic compounds; PSD-TEA packed with triethanolamine impregnated silica for acid gases; and PSD-TEA packed with phosphoric acid impregnated silica for basic gases. Many chemical compounds except for nitrogen dioxide, formic acid, and benzene showed seasonal variations with high concentrations in summer and low concentrations in winter. In particular, formaldehyde, nonanal, 2-ethyl-1-hexanol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, and ammonia concentrations showed remarkable seasonal variation. For example, the concentration of formaldehyde in February and August was 5.9 and 40 μg/m3, respectively, a difference of about 7 times. Although there were large differences in the concentrations in each house, the fluctuation pattern was almost the same every year in each house. By contrast, nitrogen dioxide, formic acid, and benzene concentrations were low in summer and high in winter. These compounds were generated by kerosine and gas stoves in winter. Long-term continuous monitoring revealed that annual mean concentrations could be estimated using data from February and August. Personal exposure concentrations could be classified into four patterns: chemicals affected by the indoor environment such as formaldehyde, chemicals affected by the outdoor environment such as ozone, chemicals affected by the occupational environment such as hexane, and background level chemicals such as benzene (without kerosine and gas stoves). Indoor and outdoor measurements are means to investigate the “health” of each environment. Personal exposure measurement using PSD-samplers is suitable for assessing the health risk of chemical compounds to humans.

Concentrations of respirable crystalline silica and radon among tanzanite mining communities in Mererani, Tanzania.

Globally, the number of small-scale miners (SSM) is estimated to be more than 25 million, but it supports the livelihoods of around 100 million individuals. In Tanzania, the number of SSM has increased from an estimated 150,000 in 1987 to ~1.5 million in 2017. The miners are at a high risk of occupational-related health challenges. The study aimed to assess the concentrations of respirable crystalline silica (RCS) and radon among the tanzanite mining communities in Simanjiro District, Tanzania. We carried out a cross-sectional study involving the Mererani mines in Tanzania. These are underground mines comprised of informally employed miners, i.e. SSM. Concentrations of RCS and radon gas were measured in 44 study units, i.e. 22 mining pits and within 22 houses in the general community, e.g. shops in the peri-mining community. A total of 132 respirable personal dust exposure samples (PDS), 3 from each of the study units were taken, but only 66 PDS from the mining pits were analysed, as this was the main interest of this study. Radon concentration was measured by continuous monitoring throughout the working shift (and overnight for residences) using AlphaGuard monitor. The medians and comparison to the reference values, OSHA USA PEL and WHO/IARC references, were done for RCS and radon, respectively, using SPSS Ver. 27.0.0). The median time-weighted average (TWA) concentration of the RCS in the mining pits was 1.23 mg/m3. Of all 66 personal dust samples from the mining pits, 65 (98.5%) had concentrations of RCS above the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 0.05 mg/m3. Mining pits had a median radon concentration of 169.50 bq/m3, which is above the World Health Organization (WHO)/International Commission on Radiation Protection (ICRP) recommended reference of 100.00 bq/m3 but not above the upper reference of 300.00 bq/m3, while the community buildings had a median radon concentration of 88.00 bq/m3. Overall, 9 (20.5%) and 17 (38.6%) radon measurements were above 300.00 bq/m3 and between 100.00 and 300.00 bq/m3 references, respectively. Specifically, in the mining pits, 9 (40.9%) test results were above 300.00 bq/m3, while none of the test results in the community was above 300.00 bq/m3. The tanzanite SSM in Mererani we highly exposed to RCS, which increases the risk of pulmonary diseases, including silicosis, tuberculosis, and pulmonary malignancies. Immediate action by OSHA Tanzania should be enforcement of wearing respirators by all miners throughout the working hours. Health education programmes to the SSM must be strengthened and OSHA Tanzania should adopt the 0.05 mg/m3 PEL, and enforce other occupational health and safety measures, including regular use of dust suppression mechanisms (water spray and wet drilling) and monitoring of RCS exposures among SSM. Monitoring of radon exposure both in the mining pits and community buildings should be conducted, and mitigation measures should be implemented in areas that exceed the reference level of 100.00 bq/m3.

Screening levels of TCS-172 NaI(Tl) survey meters used for direct thyroid measurements in nuclear disasters.

It is a challenging task to establish a feasible and robust method for the population monitoring of individuals' thyroid exposure following an accidental intake of radioiodines in a nuclear emergency, because of the time restriction. The authors previously proposed a method for such monitoring to obtain as many reliable human data as possible and one of the components is simplified measurements by conventional NaI(Tl) survey meters that are intended to be used for the initial triage to identify significantly exposed individuals and get an overall picture of the exposure levels in a target population in a timely manner. This study determined screening levels (SLs) for a conventional NaI(Tl) survey meter (model TCS-172, Hitachi, Japan) using the conversion factor (131I kBq in the thyroid per μSv h-1) that were obtained from experiments and simulations with age-specific phantoms. The results demonstrated that the derived SLs for 100mSv thyroid equivalent dose were as follows: 0.2μSvh-1 (SL1) for the age group≤5-y-olds, 0.5μSvh-1 (SL2) for the 10- and 15-y-old age groups and 1.0μSvh-1 (SL3) for adults. These SLs would be reasonably available within 1week after the intake of 131I on the safe side.

Personal exposure to fine particulate matter (PM2.5) and self-reported asthma-related health

PM2.5 (fine particulate matter ≤2.5 μm in diameter) is a key pollutant that can produce acute asthma exacerbations and longer-term deterioration of respiratory health. Individual exposure to PM2.5 is unique and varies across microenvironments. Low-cost sensors (LCS) can collect data at a spatiotemporal resolution previously unattainable, allowing the study of exposures across microenvironments. The aim of this study is to investigate the acute effects of personal exposure to PM2.5 on self-reported asthma-related health.Twenty-eight non-smoking adults with asthma living in Scotland collected PM2.5 personal exposure data using LCS. Measurements were made at a 2-min time resolution for a period of 7 days as participants conducted their typical daily routines. Concurrently, participants were asked to keep a detailed time-activity diary, logging their activities and microenvironments, along with hourly information on their respiratory health and medication use. Health outcomes were modelled as a function of hourly PM2.5 concentration (plus 1- and 2-h lag) using generalized mixed-effects models adjusted for temperature and relative humidity.Personal exposures to PM2.5 varied across microenvironments, with the largest average microenvironmental exposure observed in private residences (11.5 ± 48.6 μg/m3) and lowest in the work microenvironment (2.9 ± 11.3 μg/m3). The most frequently reported asthma symptoms, wheezing, chest tightness and cough, were reported on 3.4%, 1.6% and 1.6% of participant-hours, respectively. The odds of reporting asthma symptoms increased per interquartile range (IQR) in PM2.5 exposure (odds ratio (OR) 1.29, 95% CI 1.07–1.54) for same-hour exposure. Despite this, no association was observed between reliever inhaler use (non-routine, non-exercise related) and PM2.5 exposure (OR 1.02, 95% CI 0.71–1.48).Current air quality monitoring practices are inadequate to detect acute asthma symptom prevalence resulting from PM2.5 exposure; to detect these requires high-resolution air quality data and health information collected in situ. Personal exposure monitoring could have significant implications for asthma self-management and clinical practice.

A Critical Review on the Opportunity to Use Placenta and Innovative Biomonitoring Methods to Characterize the Prenatal Chemical Exposome.

Adverse effects associated with chemical exposures during pregnancy include several developmental and reproductive disorders. However, considering the tens of thousands of chemicals present on the market, the effects of chemical mixtures on the developing fetus is still likely underestimated. In this critical review, we discuss the potential to apply innovative biomonitoring methods using high-resolution mass spectrometry (HRMS) on placenta to improve the monitoring of chemical exposure during pregnancy. The physiology of the placenta and its relevance as a matrix for monitoring chemical exposures and their effects on fetal health is first outlined. We then identify several key parameters that require further investigations before placenta can be used for large-scale monitoring in a robust manner. Most critical is the need for standardization of placental sampling. Placenta is a highly heterogeneous organ, and knowledge of the intraplacenta variability of chemical composition is required to ensure unbiased and robust interindividual comparisons. Other important variables include the time of collection, the sex of the fetus, and mode of delivery. Finally, we discuss the first applications of HRMS methods on the placenta to decipher the chemical exposome and describe how the use of placenta can complement biofluids collected on the mother or the fetus.

Visual monitoring of lead exposure in children’s daily activities with an AuNP-based indicator

Lead exposure causes great harm to the growth and development of infants. A simple and fast approach that can be conveniently used at home is thus needed for parents to screen the potential lead sources in their children’s daily activities. Here, we developed a simple, fast, and sensitive gold nanoparticles (AuNPs)-based indicator for colorimetric Pb2+ detection. The method rationale was based on the higher affinity of Pb2+ to T30695 DNA over thioflavin T (ThT), as well as the stable and fast charge neutralization-induced assembly of AuNPs by ThT. To facilitate in-home monitoring, we arranged the reagents (AuNPs, DNA, ThT, and the buffer) and the required facilities (microplate and pipe) into a kit. Besides, the color change of the indicator AuNPs was monitored with a cell phone camera and processed with a self-developed APP. For samples closely related to children's daily activities, Pb2+ was successfully detected in saliva, sweat (simulated) and stomach fluid (simulated) extractions of water bottles, small benches, cushions, paint, lipstick, building blocks and toys. Therefore, continuous efforts are required for a lead-free life and such a kit can help the screening of lead-leaking clothing, food, shelter and toys for children.

The Effects of Drug Exposure and Single Nucleotide Polymorphisms on Aaptinib-Induced Severe Toxicities in Solid Tumors.

In this prospective study, plasma APA concentrations were quantified using liquid chromatography with tandem mass spectrometry, and 57 germline mutations were genotyped in 126 advanced solid tumor patients receiving 250 mg daily APA, a vascular endothelial growth factor receptor II inhibitor. The correlation between drug exposure, genetic factors, and the toxicity profile was analyzed. Non-small cell lung cancer (NSCLC) was more prone to APA-related toxicities and plasma concentrations of APA, and its main metabolite M1-1 could be associated with high-grade adverse events (AEs) (P < 0.01; M1-1, P < 0.01) and high-grade antiangiogenetic toxicities (APA, P = 0.034; P < 0.05), including hypertension, proteinuria, and hand-foot syndrome, in the subgroup of NSCLC. Besides, CYP2C9 rs34532201 TT carriers tended to have higher levels of APA (P < 0.001) and M1-1 (P < 0.01), whereas CYP2C9 rs1936968 GG carriers were predisposed to higher levels of M1-1 (P < 0.01). Plasma APA and M1-1 exposures were able to predict severe AEs in NSCLC patients. Dose optimization and drug exposure monitoring might need consideration in NSCLC patients with CYP2C9 rs34532201 TT and rs1936968 GG. Apatinib is an anti-VEGFR2 inhibitor for the treatment of multiple cancers. Though substantial in response, apatinib-induced toxicity has been a critical issue that is worth clinical surveillance. Few data on the role of drug exposure and genetic factors in apatinib-induced toxicity are available. Our study demonstrated a distinct drug-exposure relationship in NSCLC but not other tumors and provided invaluable evidence of drug exposure levels and single nucleotide polymorphisms as predictive biomarkers in apatinib-induced severe toxicities.

B-306 Performance Evaluation of an Automated Assay for Measurement of Tacrolimus* on the ADVIA Centaur XP System

Abstract Background Tacrolimus (FK506) (PROGRAF) is a macrolide antibiotic of fungal origin (Streptomyces tsukubaensis). Tacrolimus is an inhibitor of calcineurin, a phosphatase that activates T-cell proliferation. At the cellular level, tacrolimus binds a family of binding proteins termed FK506-binding proteins (FKBPs). The correlation between steady-state trough concentration and area under the curve (AUC) provides reliable therapeutic monitoring for tacrolimus exposure at the trough level. The objective of this study was to determine the performance characteristics of the Tacrolimus assay on the ADVIA Centaur® XP System. Methods The ADVIA Centaur Tacrolimus assay is a competitive immunoassay using direct chemiluminescent technology. Free tacrolimus in the patient sample competes with the bound tacrolimus in the solid phase for binding with the acridinium ester-labeled anti-tacrolimus antibody. The amount of tacrolimus present in the patient sample has an inverse relationship to the amount of relative light units detected by the system. Results The ADVIA Centaur Tacrolimus assay demonstrated a mean %CV of 3.1% for intra-assay and 6.0% for total precision (across a sample range of 3.10 to 26.15 ng/mL). Close correlation to LC-MS/MS was demonstrated, with r, slope, and intercept of 0.957, 0.973, and 0.475, respectively. LoD and LoQ were 0.7 ng/mL and 1.9 ng/mL, respectively. Likewise, comparison to the Atellica IM assay resulted in r, slope, and intercept of 0.966, 1.09, and -0.508, respectively. Linearity was demonstrated across a range from LoQ to 30.0 ng/mL. Tacrolimus metabolite percent cross-reactivity ranged from 1.7 to 34.2%. A panel of potential interferants including the following were tested and found not to interfere (≤10%): cephalosporin to 100 µg/mL, erythromycin to 13.8 mg/dL, phenobarbital to 10 mg/dL, rapamycin to 5 µg/mL, sulfamethoxazole to 150 µg/mL, tobramycin to 3.3 mg/dL, trimethoprim to 4.2 mg/dL, bilirubin (conjugated) to 60 mg/dL, bilirubin (direct) to 60 mg/dL, and rheumatoid factor to 500 IU/mL. Conclusion The resulting data demonstrates that the ADVIA Centaur Tacrolimus assay is an accurate and precise method of quantifying tacrolimus concentration in EDTA whole-blood samples. *Assay under development by Randox Laboratories Ltd. for Siemens Healthineers. Not available for sale. Future availability cannot be guaranteed.

Continuous aerosol monitoring and comparison of aerosol exposure based on smoke dispersion distance and concentrations during oxygenation therapy

This study evaluated the aerosol exposure risks while using common noninvasive oxygenation devices. A simulated mannequin was designed to breathe at a minute ventilation of 20 L/min and used the following oxygen-therapy devices: nasal cannula oxygenation (NCO) at 4 and 15 L/min, nonrebreathing mask (NRM) at 15 L/min, simple mask at 6 L/min, combination of NCO at 15 L/min and NRM at 15 L/min, high-flow nasal cannula (HFNC) at 50 L/min, and flush rate NRM. Two-dimension of the dispersion distance and the aerosol concentrations were measured at head, trunk, and foot around the mannequin for over 10 min. HFNC and flush-rate NRM yielded the longest dispersion distance and highest aerosol concentrations over the three sites of the mannequin than the other oxygenation devices and should use with caution. For flow rates of < 15 L/min, oxygenation devices with mask-like effects, such as NRM or NCO with NRM, decreased aerosol dispersion more effectively than NCO alone or a simple mask. In the upright position, the foot area exhibited the highest aerosol concentration regardless of the oxygenation device than the head–trunk areas of the mannequin. Healthcare workers should be alert even at the foot side of the patient while administering oxygenation therapy.

Is Occupational Arsenic Exposure a Possible Causative Agent of Breast Cancer for a Young Female Laboratory Technician? A Case-Study

A 28-year-old female laboratory technologist who was exposed to highly concentrated inorganic arsenic for 7 years, 25 hours a week, presented with left breast cancer. When most epidemiologic evidence reported by the IARC supported the relationship between arsenic exposure and cancers of lung, skin and bladder; literature had documented increased risk of breast cancer in specific populational subgroups due to the estrogen-like activity of arsenic. The causal assessment of occupational cancer is challenging due to the lack of relevant data on the worker’s biological monitoring and environmental exposure monitoring data, together with the insufficient genetic composition information like BRCA1 gene. Moreover, the poor work practice and hygiene had made the exposure through dermal contact and digestion possible. The interpretation of work causal relationship while distinct occupational cancer from those of non-occupational must consider individual susceptibility as low-level short-period exposure might increase the risk for certain worker. Therefore, a systematically collected medical surveillance data along with industry hygiene data is highly recommended in order to assist in the refinement of human dose-response relationship of specific work carcinogen

CEC06-05: Examples of pesticide occupational exposure monitoring in the field

CEC06-05: Examples of pesticide occupational exposure monitoring in the field

Evaluation of Radiation Exposure and Image Quality in Congenital Catheterization Laboratory; A Single Centre Comparative Study Using Different Acquisition Modes

Abstract Background The exposure to ionizing radiation delivered during the catheterization procedures has various negative biological effects to the patient, so concern has risen sharply about radiation hazards over the past decade.While angiography imaging system vendors have all made great strides with new technologies that reduce the amount of x-rays needed while maintaining excellent image quality, the procedures have become more complex, lasting longer and require more imaging than standard procedures. Aim of the Work To study the effect of lowering radiation dose by using a fluoro angiography on image quality in pediatric cardiac catheterization. Patients and Methods We studied 90 patients who underwent cardiac cath. for CHD at Ain Shams University hospital. Patients were randomized into three groups according to mode of acquisition used in procedure (fluro angiography only–cine angiography only–mixed). Radiation indices were measured, also image quality questionnaire was filled by operators after each procedure. Results statistically significant difference between three modalities of acquisition as regard the radiation indices (DAP, total air kemra, fluoroscopy time) with p value &amp;lt;0.005. While operators satisfaction with image was nearly the same in the three groups with median score 68.5 (p value 0.681). Conclusion Based on the results of the current study it can be concluded that: Mixed imaging acquisition had highest radiation exposure indices in comparison with other two acquisition modalities (fluro angiography only – cine angiography only), with statistically significant difference with fluro only mode (p value &amp;lt;0.005), and no statistically significant deference with cine only mode. Complexity of the procedures &amp; increased the cath. lab machine imaging protocol to 30 fps and repeat the same injection in the cine mode after fluro mode were the most important factors that made mixed acquisition had the highest radiation indices and exposure. Image quality and operators satisfaction were nearly the same in three acquisition modes (fluro-cine-mixed) with median image score 68.5 (p value 0.681), in expense of more radiation exposure in mixed mode. Increase operators awareness to radiation and continuous monitoring of radiation exposure with application of ALARA principles is important to reduce radiation exposure.

Obesity-related cardiometabolic indicators modify the associations of personal noise exposure with heart rate variability: A further investigation on the Study among Obese and Normal-weight Adults (SONA)

Elucidating the associations between environmental noise and heart rate variability (HRV) would be beneficial for the prevention and control of detrimental cardiovascular changes. Obese people have been found to manifest heightened susceptibility to the adverse effects of noise on HRV. However, the underlying mechanisms remain unclear. Based on 53 normal-weight and 44 obese young adults aged 18–26 years in Beijing, China, this study aimed to investigate the role of obesity-related cardiometabolic indicators for associations between short-term environmental noise exposure and HRV in the real-world context. The participants underwent personal noise exposure and ambulatory electrocardiogram monitoring using portable devices at 5-min intervals for 24 continuous hours. Obesity-related blood pressure, glucose and lipid metabolism, and inflammatory indicators were subsequently examined. Generalized mixed-effect models were used to estimate the associations between noise exposure and HRV parameters. The C-peptide, homeostasis model assessment of insulin resistance (HOMA-IR), and leptin levels were higher in obese participants compared to normal-weight participants. We observed amplified associations between short-term noise exposure and decreases in HRV among participants with higher C-peptide, HOMA-IR, and leptin levels. For instance, a 1 dB(A) increment in 3 h-average noise exposure level preceding each measurement was associated with changes of −0.20% (95%CI: −0.45%, 0.04%) and −1.35% (95%CI: −1.85%, −0.86%) in standard deviation of all normal to normal intervals (SDNN) among participants with lower and higher C-peptide levels, respectively (P for interaction <0.05). Meanwhile, co-existing fine particulate matter (PM2.5) could amplify the associations between noise and HRV among obese participants and participants with higher C-peptide, HOMA-IR, and leptin levels. The more apparent associations of short-term exposure to environmental noise with HRV and the effect modification by PM2.5 may be partially explained by the higher C-peptide, HOMA-IR, and leptin levels of obese people.

Effects of cyclophosphamide and mitomycin C on radiation-induced transcriptional biomarkers in human lymphoblastoid cells

Purpose Ionizing radiation (IR)-induced transcriptional changes are considered a potential biodosimetry for dose evaluation and health risk monitoring of acute or chronic radiation exposure. It is crucial to understand the impact of confounding factors on the radiation-responsive gene expressions for accurate and reproducible dose assessment. This study aims to explore the potential influence of exposures to chemotherapeutic agents such as cyclophosphamide (CP) and mitomycin C (MMC) on IR-induced transcriptional biomarkers. Methods The human B lymphoblastoid cells (AHH-1) were exposed to 0, 20, 50, 100, 200 and 500 μg/ml CP or 0, 0.025, 0.05, 0.1 and 1 μg/ml MMC, respectively. The appropriate concentrations of CP and MMC were added for 1 h before irradiation with 0, 2, 4 and 6 Gy of 60Co γ-rays at a dose rate of 1 Gy/min. Cell viability was evaluated by CCK-8 assay. The gene expression responses of 18 radiation-induced transcriptional biomarkers were examined at 24 h after exposures to CP and MMC, respectively. The expression levels of five crucial DNA interstrand crosslinks (ICLs) repair genes were also evaluated. The biodosimetry models were established based on the specific radiation-responsive gene combinations. Results The baseline transcriptional levels of the 18 selected genes were slightly affected by CP treatment in the absence of IR, while the transcript responses to IR could be inhibited as the concentration of CP up to 50 μg/ml. MMC treatment up-regulated the background levels in most radiation-responsive gene expressions. Of 18 genes, only the relative mRNA expression levels of CDKN1A and BBC3 were repressed after treatment with IR and MMC in combination. The relative mRNA level of RAD51 was significantly up-regulated after exposure to CP, while the expression of FANCD2, RAD51 and BLM showed an overall increase in response to MMC treatment. After irradiation, the relative mRNA expression levels of FANCD2, BRCA2 and RAD51 exhibited dose-dependent increases in IR alone and MMC treatment groups. In addition, the biodosimetry models were established using 2-4 radiation-responsive genes based on different radiation exposure scenarios. Conclusion Our findings suggested that IR-induced gene expression changes were slightly affected after exposure to a relatively low concentration of CP and MMC. Gene expression combinations might improve the broad applicability of transcriptional biodosimetry across diverse radiation exposures.

Australia’s Ongoing Challenge of Legacy Asbestos in the Built Environment: A Review of Contemporary Asbestos Exposure Risks

Asbestos remains ubiquitous in the Australian built environment. Of the 13 million tonnes of asbestos products installed in earlier decades, an estimated 50% remain in situ today. Because of the extensive past use of asbestos, and the increasing age of these products, the potential for exposure to asbestos fibres in both indoor and outdoor environments remains high, even while the actual asbestos exposure levels are mostly very low. Sources of these exposures include disturbance of in situ asbestos-containing materials (ACMs), for example during renovations or following disaster events such as fires, cyclones and floods. Our understanding of the risk of asbestos-related disease arising from long-term low-level or background exposure, however, is poor. We provide the most up-to-date review of asbestos exposure risks currently affecting different groups of the Australian population and the settings in which this can manifest. From this, a need for low-level asbestos monitoring has emerged, and further research is required to address whether current exposure monitoring approaches are adequate. In addition, we make the case for proactive asbestos removal to reduce the risk of ongoing asbestos contamination and exposure due to deteriorating, disturbed or damaged ACMs, while improving long-term building sustainability, as well as the sustainability of limited resources.