Post-shift Samples Research Articles

Urinary benzyl alcohol and hippuric acid in workers exposed to benzyl alcohol during paint stripping work.

This research aimed to develop a reliable gas chromatography-mass spectrometry (GC-MS) method for detecting urinary benzyl alcohol (BeOH) concentrations and assess its suitability as a biomarker for occupational BeOH exposure. Thirteen male participants exposed to BeOH during paint stripping work provided preshift and postshift urine samples, and their personal exposure concentrations were measured. Meanwhile, a control group of 10 nonexposed workers contributed urine samples. The newly developed GC-MS method met regulatory guidelines. The personal exposure concentrations of BeOH ranged from 8.4 to 45.2mg/m3. Postshift urine samples from exposed participants showed significant BeOH and hippuric acid (HA) concentration increases compared to preshift samples (BeOH, post-/pre-shift geometric mean (GM) ratio = 7.5-7.8, p < 0.001; HA, post-/pre-shift GM ratio = 4.3-4.5, p < 0.001). These levels were considerably higher than those in postshift samples from the nonexposed control group (BeOH, exposed-/nonexposed-workers GM ratio = 14.8-19.0, p < 0.001; HA, exposed-/nonexposed-workers GM ratio = 12.1-15.3, p < 0.001), even after urine density correction. Urinary BeOH and HA can serve as potential biomarkers of occupational exposure to BeOH. More specifically, BeOH might serve as a superior biomarker than HA because it is apparently less influenced by confounding factors such as dietary intake and genetic polymorphism of low-Km aldehyde dehydrogenase (ALDH2). The findings will improve workplace safety measures and protocols, assisting healthcare professionals in diagnosing and managing exposure-related health issues, thereby potentially reducing the risk of occupational exposure to BeOH.

Workplace induced heat-related-illness and kidney disorders among coal cutters of underground mines

Workers in hot underground coal mines could develop heat-related illnesses, (especially skin, digestion and kidney problems), as compared to workers in non-hot mines. This study found severity of this situation by comparing heat illness symptoms, core body and skin temperature and kidney malfunctioning amongst workers of both types of mines. Ingestible thermometric pills (sending readings to Sensor Electronic Module every 15 s), skin temperature probes (connected to various body parts and sending readings to loggers) and laboratory analysis of pre- and post-shift samples of blood and urine, US-NIOSH-HETA-2012 sheet to survey symptoms, were used to collect data from 50 workers (25 from five hot mines (G1) and 25 from five non-hot mines (G2)). Two mine groups showed significant differences ( p-value &lt;.001) regarding wet-bulb globe temperature, dry-bulb temperature and relative humidity. The highest core body temperature was 38.8°C in G1 and 37.9°C in G2. In intra-group comparison for kidney functioning, post-shift samples showed haematocrit (%) was reduced to 43.6 ± 2.1 from 45.4 ± 1.4 in G1 and to 44.0 ± 2.9 from 45.0 ± 0.75 in G2, and estimated glomerular filtration rate was reduced from 100 ± 19 to 94 ± 0 mL/min/1.72 m2 in G1 and to 113 ± 15 from 115 ± 19a in G2 workers. The comparison showed hot mines could induce heat-related illnesses which would necessitate intervention to reduce exposure.

39 Investigation of Workplace Silica Exposures Using Novel Samplers and Methods

Abstract Scientists from the Health and Safety Executive visited a range of workplaces where there was the potential for exposure to silica. The aim of the visits was to determine potential worker exposures to dust and respirable crystalline silica by static air monitoring and exhaled breath condensate (EBC). To evaluate potential airborne exposures low-cost particle monitors were deployed alongside more established scientific equipment. On site airborne dust concentrations were measured at different locations using two photometers, an optical particle counter (OPC) and a respirable cyclone. The size distribution was measured in real-time using a low-cost OPC and by offline analysis of a polycarbonate membrane filter housed inside an inhalable sampler using a Coulter Counter III. Pre and post shift samples of EBC were taken from 29 workers, with samples analysed by single particle inductively coupled plasma tandem mass spectrometry to measure Si-containing particles. The real-time air monitoring data showed sustained increased concentrations or peaks corresponding to specific areas or activities, therefore indicating the tasks and/or locations most likely to contribute to worker exposure. The low-cost instruments were also effective in highlighting site locations and tasks most likely to contribute to worker exposure. An approach combining multiple sampling techniques provided a good characterisation of airborne, silica containing dusts. The EBC results consistently showed increased numbers of silicon containing particles post-shift compared with pre-shift.

106 Investigation of Workplace Silica Exposures Using Novel Samplers and Methods

Abstract Scientists from the Health and Safety Executive visited a manufacturing workplace where coatings are prepared by loading powders, frit and water into various sized mills. The aim of the visit was to determine potential worker exposures to dust and respirable crystalline silica by static air monitoring and exhaled breath condensate. Low-cost particle monitors were deployed alongside more established scientific equipment. Airborne dust concentrations were measured at three site locations using two photometers, an optical particle counter (OPC) and a respirable cyclone. The size distribution was measured in real-time using a low-cost OPC and by offline analysis of a polycarbonate membrane filter housed inside an inhalable sampler. Pre and post shift samples of exhaled breath condensate were collected from 6 workers, with samples analysed by single particle inductively coupled plasma mass spectrometry to measure the number and size of silicon containing particles present. The real-time air monitoring data at all three locations showed peaks in airborne concentrations corresponding to the loading activities and indicating the tasks most likely to contribute to worker exposure. The average concentration of respirable dust measured closest to the process was 0.13 mg.m-3 for the 8-hour shift. The low-cost monitors provided good information about the changes in concentration over time relating to worker activities.

Biological Monitoring of Urinary Fluoride Among Phosphate Fertiliser Production Industrial Workers

Objectives: Fluoride pollution at the workplace environment arises mostly due to anthropogenic activities. The workers working in phosphate fertilizer industry might have chronic exposure to excessive fluoride which can cause adverse health effects. Therefore, the present study was designed to assess urinary fluoride levels in occupationally exposed workers. Methods: In this study, pre and post-shift urinary samples were collected from phosphate fertilizer industry male workers (n=53). Fluoride levels in urine samples were analysed using an Ion Selective Electrode (ISE). Findings: The mean concentration of pre-shift and post-shift urinary fluoride levels were 2.141.35 and 2.422.02 mg/g of urinary creatinine respectively. Workers’ pre-shift mean urine fluoride levels were categorised according to their working departments. Workers from the manufacture plat of Single Super Phosphate (SSP), Granular Single Super Phosphate (GSSP), maintenance, and administration had fluoride levels of 2.871.88, 2.431.01, 2.161.30, and 0.920.601 mg/g of urine creatinine, respectively. Similarly, the post-shift urinary fluoride levels were 3.683.00, 2.641.85, 2.241.78 and 1.140.53 mg/g of urinary creatinine in these departments respectively. One-way analysis of variance shown significant difference in urine fluoride concentrations between pre-shift (ANOVA, df=3, F=4.717; p=0.006) and post-shift samples (ANOVA, df=3, F=2.895; p=0.044). About 22.64 % of subjects in the pre-shift and 3.77% of subjects in the post-shift had exceeded the urinary fluoride limits prescribed by various statutory agencies. Novelty: Based on pre-shift and post-shift work exposure assessments, this study adds new knowledge to scientific research on the fluoride exposure among phosphate fertiliser sector workers. While there is sporadic information on fluoride levels among various other occupational groups, very few reports reported the fluoride levels in fertilizer industryworkers. Outcomes of this study will help to identify the source of fluoride and extent of fluoride exposure so as to suggest the mitigation measure to control fluoride exposure at occupational settings. Keywords: Biological monitoring; Fluoride exposure; Urinary fluoride; Occupational fluoride exposure; Fertilizer industry workers

Exposure assessment of polycyclic aromatic hydrocarbons in refined coal tar sealant applications.

Refined coal tar sealant (RCTS) emulsions are used to seal the surface of asphalt pavement. Nine of the 22 polycyclic aromatic hydrocarbons (PAHs) evaluated in this study are classified as known, probable, or possible human carcinogens. Exposure assessment research for RCTS workers has not been published previously. The overall objective of this study was to develop a representative occupational exposure assessment of PAH exposure for RCTS workers based on worksite surveys. The specific aims were to: 1) quantify full-shift airborne occupational exposures to PAHs among RCTS workers; 2) quantify workers' dermal exposures to PAHs; 3) quantify biomarkers of PAH exposure in workers' urine; 4) identify specific job titles associated with RCTS exposure; and 5) apply these results to a biological exposure index to assess risk of potential genotoxicity from occupational exposures. A total of twenty-one RCTS workers were recruited from three companies. Personal and area air samples were collected using a modification of NIOSH Method 5515. Dermal exposure was assessed by hand and neck wipes before and after shifts. Twenty-two PAHs were quantified via gas chromatography-mass spectrometry selected ion monitoring. Internal dose was estimated by quantifying select PAH metabolites in pre- and post-shift urine samples using on-line solid phase extraction-high performance liquid chromatography-tandem mass spectrometry. PAH levels in the worker breathing zones were highest for naphthalene, acenaphthene, and phenanthrene, with geometric means of 52.1, 11.4, and 9.8μg/m3, respectively. Hand wipe levels of phenanthrene, fluoranthene and pyrene were the highest among the 22 PAHs with geometric means of 7.9, 7.7, and 5.5μg/cm2, respectively. Urinary PAH biomarkers for naphthalene, fluorene, phenanthrene, and pyrene were detected in all workers and were higher for post-shift samples than those collected pre-shift. Urinary concentrations of the metabolite 1-hydroxypyrene were greater than the American Conference of Governmental Industrial Hygienists (ACGIH) Biological Exposure Index (BEI) for this metabolite in 89 percent of post-shift samples collected on the final day of the work week or field survey. Statistically significances were found between concentrations of fluorene, naphthalene, and phenanthrene in the breathing zone of workers and their corresponding urinary PAH biomarkers. Workers were placed in two work place exposure groups: applicators and non-applicators. Applicators had higher total PAH concentrations in personal breathing zone (PBZ) air samples than non-applicators and were more likely to have post-shift hand wipe concentrations significantly higher than pre-shift concentrations. Concentrations of post-shift urinary biomarkers were higher, albeit not significantly, for applicators than non-applicators. The exposure results from RCTS worker samples cannot be explained by proximal factors such as nearby restaurants or construction. Air and skin concentration levels were substantially higher for RCTS workers than previously published levels among asphalt workers for all PAHs. PAH profiles on skin wipes were more consistent with RCTS sealant product than air samples. Last day post-shift urinary concentrations of 1-hydroxypyrene greatly exceeded the ACGIH BEI benchmark of 2.5μg/L in 25 of 26 samples, which suggests occupational exposure and risk of genotoxicity. When pyrene and benzo[a]pyrene were both detected, concentration ratios from personal exposure samples were used to calculate the adjusted BEI. Concentrations of 1-hydroxypyrene exceeded the adjusted BEIs for air, hand wipes, and neck wipes in most cases. These results indicate the need to increase safety controls and exposure mitigation for RCTS workers.

Three-Year Study of Markers of Oxidative Stress in Exhaled Breath Condensate in Workers Producing Nanocomposites, Extended by Plasma and Urine Analysis in Last Two Years.

Human data concerning exposure to nanoparticles are very limited, and biomarkers for monitoring exposure are urgently needed. In a follow-up of a 2016 study in a nanocomposites plant, in which only exhaled breath condensate (EBC) was examined, eight markers of oxidative stress were analyzed in three bodily fluids, i.e., EBC, plasma and urine, in both pre-shift and post-shift samples in 2017 and 2018. Aerosol exposures were monitored. Mass concentration in 2017 was 0.351 mg/m3 during machining, and 0.179 and 0.217 mg/m3 during machining and welding, respectively, in 2018. In number concentrations, nanoparticles formed 96%, 90% and 59%, respectively. In both years, pre-shift elevations of 50.0% in EBC, 37.5% in plasma and 6.25% in urine biomarkers were observed. Post-shift elevation reached 62.5% in EBC, 68.8% in plasma and 18.8% in urine samples. The same trend was observed in all biological fluids. Individual factors were responsible for the elevation of control subjects’ afternoon vs. morning markers in 2018; all were significantly lower compared to those of workers. Malondialdehyde levels were always acutely shifted, and 8-hydroxy-2-deoxyguanosine levels best showed chronic exposure effect. EBC and plasma analysis appear to be the ideal fluids for bio-monitoring of oxidative stress arising from engineered nanomaterials. Potential late effects need to be targeted and prevented, as there is a similarity of EBC findings in patients with silicosis and asbestosis.

Application of biological monitoring for exposure assessment of 1.3 Butadiene.

1, 3-Butadiene is an important industrial compound. Based on sufficient evidence of carcinogenicity in laboratory animals and humans, the International Agency for Research on Cancer, in 1999, classified 1, 3-Butadiene as a probable carcinogen to humans (group 2A). The potential for exposure to vehicle exhaust containing these chemical compounds is very noticeable in urban locations. Exposure to incomplete combustion of gasoline has been a long time concern in many occupational fields, including policemen, service stations, and the petroleum industry but in Iran has rarely been studied. This study designed to determine the exposure levels for traffic policemen and gas station workers during routine work shift, by biological monitoring. With this aim, 25 policemen engaged in traffic control, 25 gas station workers and 25 occupationally non-exposed persons were investigated. Spot urine samples were obtained prior to and at the end of the work shift from each subject. The urinary levels of selected urinary metabolites (MHBMA and DHBMA) were determined by using LC-MS/MS. There were significant differences among the mean urinary concentrations of DHBMA in pre-shift samples of policemen, gas station workers and occupationally non-exposed persons. The mean urinary concentrations of DHBMA differed significantly among post-shift samples of policemen and gas station (ANOVA: p < 0.05 and Kruskal-Wallis test: p < 0.05). There was a significant difference in DHBMA concentrations between job categories (p < 0.05 by ANOVA and Kruskal-Wallis test), and policemen and gas station workers were found to be probably the most exposed groups in this study.

Assessing BTEX exposure among workers of the second largest natural gas reserve in the world: a biomonitoring approach.

Urinary benzene, toluene, ethylbenzene, and xylenes (BTEX) can be used as a reliable biomarker of exposure to these pollutants. This cross-sectional study aimed to employ biomonitoring to assess BTEX exposure among South Pars Gas Field (SPGF) workers in Assaluyeh, Iran. Forty employees who were working on the site were recruited as the case group. Besides, 31 administrative employees were recruited as the control group. Pre-shift and post-shift spot urine samples were collected from the subjects in the case group, while the subjects in the control group provided mid-morning urine samples. Overall, 111 urine samples, including 80 samples from the case group and 31 samples from the controls, were collected. Gas chromatography-mass spectrometry (GC/MS) was used to determine the urinary levels of BTEX compounds. The median urinary levels of benzene, toluene, ethylbenzene, m,p-xylene, and o-xylene in the post-shift samples of the exposed group were 1.24, 2.28, 0.5, 1.32, and 1.5μg/l, respectively. Significant differences were observed in urinary BTEX levels among smokers and non-smokers in both studied groups (p < 0.05). Accordingly, the median urinary BTEX concentrations in smokers were 2 to 6.5 times higher than the corresponding values in non-smoker subjects. Smoking status was the only predictor of the urinary BTEX concentration. Our findings revealed that refinery workers are exposed to significant levels of BTEX compounds. Considering the health risks associated with BTEX exposure for refinery workers, implementation of suitable control strategies, such as using appropriate personal protective equipment and improving on-site ventilation systems, are recommended reducing their exposure to BTEX via the inhalation.

The genotoxic effects in the leukocytes of workers handling nanocomposite materials

The extensive development of nanotechnologies and nanomaterials poses a number of questions to toxicologists about the potential health risks of exposure to nanoparticles (NP). In this study, we analysed DNA damage in the leukocytes of 20 workers who were long-term exposed (18 ± 10 years) to NP in their working environment. Blood samples were collected in September 2016, before and after a shift, to assess (i) the chronic effects of NP on DNA (pre-shift samples) and (ii) the acute effects of exposure during the shift (the difference between pre- and post-shift samples). The samples from matched controls were taken in parallel with workers before the shift. Leukocytes were isolated from heparinised blood on a Ficoll gradient. The enzyme-modified comet assay (DNA formamido-pyrimidine-glycosylase and endonuclease III) demonstrated a considerable increase of both single- and double-strand breaks in DNA (DNA-SB) and oxidised bases when compared with the controls (2.4× and 2×, respectively). Acute exposure induced a further increase of DNA-SB. The welding and smelting of nanocomposites represented a higher genotoxic risk than milling and grinding of nanocomposite surfaces. Obesity appeared to be a factor contributing to an increased risk of oxidative damage to DNA. The data also indicated a higher susceptibility of males vs. females to NP exposure. The study was repeated in September 2017. The results exhibited similar trend, but the levels of DNA damage in the exposed subjects were lower compared to previous year. This was probably associated with lower exposure to NP in consequence of changes in nanomaterial composition and working operations. The further study involving also monitoring of personal exposures to NP is necessary to identify (i) the main aerosol components responsible for genotoxic effects in workers handling nanocomposites and (ii) the primary cause of gender differences in response to NP action.

JA:2021-6. Effectiveness of a Low-cost Intervention: Changes to Cytokines and Microbiome among Bioaerosol Exposed Dairy Workers

ABSTRACT Purpose: Livestock workers experience an increased burden of bioaerosol-induced respiratory disease. We have previously demonstrated that dairy operations generate bioaerosols spanning the inhalable size fraction. These aerosols contained complex bacterial communities and inflammagens. Because those particles with an aerodynamic diameter between 10 and 100 μm are known to deposit in the nasopharyngeal region, we believe that exposure health outcomes in the upper respiratory tract are important and need consideration, especially in the context of the nasal microbiome (i.e., collection of bacterial communities suggested to play a key role in health and disease). Methods: We evaluated the effectiveness of a hypertonic saline nasal lavage in reducing inflammatory responses in dairy workers from a high-volume dairy operation. We collected inhalable personal breathing zone (PBZ) samples and pre-/post-shift nasal lavage samples from each participant over five consecutive days. The treatment group (n = 5) received hypertonic saline, while the control group (n = 5) received normotonic saline. PBZ samples were analyzed for particulate concentrations and endotoxin using gravimetric and enzymatic methods, respectively. Pro- and anti-inflammatory cytokines (i.e., IL-8, IL-10, and TNF-α) were measured from nasal lavage samples using a multiplex assay. To measure the air and nasal microbiomes, lavage and dust samples were analyzed using 16S rRNA sequencing. Results/Findings: Inhalable dust concentrations ranged from 0.15 to 1.9 mg/m3. Significant differences in pro-inflammatory cytokines were observed between treatment and control groups for IL-6. Contrary to the hypothesis, IL-6 concentrations were higher in the treatment group than the control group. However, the treatment group had significantly higher IL-10 (anti-inflammatory) concentrations than the control group. Distinct bacterial communities were observed in pre- and post-shift lavage samples, with post-shift communities more closely resembling those found in dust samples. Practical Implications: Based on pilot results, the intervention was successful in upregulating anti-inflammatory cytokines and promoting changes in the nasal microbiome. Therefore, more research is warranted to determine if a hypertonic nasal rinse is an effective intervention that does not cause adverse perturbations to the microbiome.

Electrolyte Balance And Hydration Status During Wildland Fire Suppression

INTRODUCTION: Our laboratory has previously demonstrated the total energy fluid demands of wildland firefighters (WLFF) during arduous fire suppression. However, it remains unclear how current hydration strategies, occupational activity, and fire line provisions may alter overall hydration and electrolyte balance. PURPOSE: To determine WLFF fluid retention and urine production as influenced by environmental conditions, self-selected hydration practices, and work output during fire suppressions shifts. METHODS: 59 WLFF (9 female, 50 male; 29±6 yr) from various crew types were deployed to fire incidents across the United States during the 2019 fire season and were observed throughout a single work shift. Before and after shifts, a measure of nude body weight was obtained. In a subset of subjects (n=25), pre and post-shift blood samples were also drawn to evaluate serum electrolytes. Fireline-certified researchers monitored fluid intake and urine output parameters (frequency, specific gravity [USG], volume) in real-time via observational data capture using graduated cylinder, refractometer, and mobile tablets. Dependent t-tests were performed for all comparative analyses and statistical significance was established at p<0.05. RESULTS: WLFF worked shifts of 13.9±1.1 hr, during which 4.7±1.6 L of water was consumed. WLFF eliminated 2.3±1.1 L via 5.7±2.7 voids (412±192 mL.void-1). There were no noted differences in USG from morning voids compared to those measured post meridiem (1.0106±0.0147 and 1.0106±0.0187 for AM and PM USG, respectively; p>0.05). No changes in nude body weight were observed across the work shift (80±13.4 and 79.8±13.2 kg for pre- and post-shift, respectively; p>0.05). Serum sodium and potassium did not change between pre- and post-shift blood draws (pre = 142±2 and 4.3±0.3, post = 141±2 and 4.2±0.3, respectively; p>0.05). CONCLUSION: These results demonstrate adequate fireline electrolyte provisions and currently employed WLFF hydration strategies. Moreover, the uniformity of pre- and post-shift measures (body weight, serum electrolytes) demonstrates that USG alone is not adequately indicative of hydration status during extended occupational stress.

Possible role of n-hexane as an endocrine disruptor in occupationally exposed women at reproductive age

Human exposure to n-hexane has been associated with subfertility and, experimentally, with a decrease in follicular development. In order to assess occupational exposure to n-hexane on ovarian function and gonadotropic hormones, we studied Mexican women labouring in a leather shoe factory (n = 34). Individual environmental levels for seven solvents, n-hexane included, were measured; also, urinary 2,5-hexanedione (2,5-HD) was determined. For ovarian function and hormonal status, FSH, LH, oestradiol and anti-Müllerian hormone (AMH) levels were determined. We performed all determinations also in a reference group, administrative workers with no exposure to solvents (n = 32). Results: N-hexane and urinary 2,5-HD levels were higher in exposed group (p < 0.001). More cases of oligomenorrhea as well as longer time for getting pregnant were observed in exposed women compared with controls; a positive association was found between menstrual cycle length and “time for getting pregnant” (p = 0.010); significant associations between FSH serum levels and 2,5-HD urinary levels (post-shift sample) were observed in non-smokers participants presenting oligomenorrhea from exposed group. Also, we found a trend for lower oestradiol levels in exposed participants with current smoking habit (p = 0.059). Conclusions: 2,5-HD urinary levels are associated with decreased gonadotropins levels; hence, n-hexane should be considered an endocrine disruptor in reproductive-age women.

Assessment of exposure of gas station attendants in Sri Lanka to benzene, toluene and xylenes

Exposure to benzene, toluene and p-, m-, o-xylene (BTX) was studied in 29 gas station attendants and 16 office workers in Sri Lanka. The aim of this study was to assess the exposure level and identify potential exposure mitigating measures. Pre- and post-shift samples of end-exhaled air were collected and analysed for BTX on a thermal desorption gas chromatography mass spectrometry system (TD-GC-MS). Urine was collected at the same timepoints and analysed for a metabolite of benzene, S-phenyl mercapturic acid (SPMA), using liquid chromatography-mass spectrometry (LC-MS). Environmental exposure was measured by personal air sampling and analysed by gas chromatography flame ionization detection (GC-FID). Median (range) breathing zone air concentrations were 609 (65.1-1960) μg/m3 for benzene and 746 (<5.0-2770) μg/m3 for toluene. Taking into account long working hours, 28% of the measured exposures exceeded the ACGIH threshold limit value (TLV) for an 8-h time-weighted average of 1.6 mg/m3 for benzene. Xylene isomers were not detected. End-exhaled air concentrations were significantly increased for gas station attendants compared to office workers (p < 0.005). The difference was 1-3-fold in pre-shift and 2-5-fold in post-shift samples. The increase from pre-to post-shift amounted to 5-15-fold (p < 0.005). Pre-shift BTX concentrations in end-exhaled air were higher in smokers compared to non-smokers (p < 0.01). Exposure due to self-reported fuel spills was related to enhanced exhaled BTX (p < 0.05). The same was found for sleeping at the location of the gas station between two work-shifts. Benzene in end-exhaled air was moderately associated with benzene in the breathing zone (r = 0.422; p < 0.001). Median creatinine-corrected S-phenyl mercapturic acid (SPMA) was similar in pre- and post-shift (2.40 and 3.02 μg/g) in gas station attendants but increased in office workers (from 0.55 to 1.07 μg/g). In conclusion, working as a gas station attendant leads to inhalation exposure and occasional skin exposure to BTX. Smoking was identified as the most important co-exposure. Besides taking preventive measure to reduce exposure, the reduction of working hours to 40 h per week is expected to decrease benzene levels below the current TLV.

Benzene Exposure and Biomarkers in Alveolar Air and Urine Among Deck Crews on Tankers Transporting Gasoline.

IntroductionIncreased rates of leukaemia have been found among tanker crews. Occupational exposures to the leukomogen benzene during loading, unloading, and tank cleaning are possible causes. Studies on older types of tankers carrying gasoline with most handling being done manually have revealed important exposures to benzene. Our study explores benzene exposures on tankers with both automatic and manual systems. Correlations between benzene exposure and benzene in alveolar air (AlvBe), benzene in urine (UBe), and trans,trans-muconic acid (ttMA) in urine were investigated.MethodsForty-three male seafarers (22 deck crewmembers and 21 not on deck) on five Swedish different product and chemical tankers transporting 95- or 98-octane gasoline were investigated between 1995 and 1998. The tankers used closed systems for the loading and unloading of gasoline but stripping and tank cleaning were done manually. Benzene in respiratory air was measured using personal passive dosimeters during a 4-h work shift. Samples for biomarker analyses were collected pre- and post-shift. Smoking did occur and crewmembers did not use any respiratory protection during work.ResultsThe average 4-h benzene exposure level for exposed was 0.45 mg m−3 and for non-exposed 0.02 mg m−3. Benzene exposure varied with type of work (range 0.02–143 mg m−3). AlvBe, UBe, and ttMA were significantly higher in post-shift samples among exposed and correlated with exposure level (r = 0.89, 0.74, and 0.57, respectively). Smoking did not change the level of significance among exposed.DiscussionBenzene in alveolar air, unmetabolized benzene, and ttMA in urine are potential biomarkers for occupational benzene exposure. Biomarkers were detectable in non-exposed, suggesting benzene exposure even for other work categories on board tankers. Work on tankers carrying gasoline with more or less closed handling of the cargo may still lead to significant benzene exposure for deck crewmembers, and even exceed the Swedish Occupational Exposure Limit (OEL; 8-h time-weighted average [TWA]) of 1.5 mg m−3.

Assessment of spray polyurethane foam worker exposure to organophosphate flame retardants through measures in air, hand wipes, and urine

Tris(1-chloro-2-propyl) phosphate (TCPP, also referenced as TCIPP), a flame retardant used in spray polyurethane foam insulation, increases cell toxicity and affects fetal development. Spray polyurethane foam workers have the potential to be exposed to TCPP during application. In this study, we determined exposure to TCPP and concentrations of the urinary biomarker bis(1-chloro-2-propyl) phosphate (BCPP) among 29 spray polyurethane foam workers over 2 work days. Work was conducted at residential or commercial facilities using both open-cell (low density) and closed-cell (high density) foam. Study participants provided two personal air samples (Day 1 and Day 2), two hand wipe samples (Pre-shift Day 2 and Post-shift Day 2), and two spot urine samples (Pre-shift Day 1 and Post-shift Day 2). Bulk samples of cured spray foam were also analyzed. Sprayers were found to have significantly higher TCPP geometric mean (GM) concentration in personal air samples (87.1 μg/m3), compared to helpers (30.2 μg/m3; p = 0.025). A statistically significant difference was observed between TCPP pre- and post-shift hand wipe GM concentrations (p = 0.004). Specifically, TCPP GM concentration in post-shift hand wipe samples of helpers (106,000 ng/sample) was significantly greater than pre-shift (27,300 ng/sample; p < 0.001). The GM concentration of the urinary biomarker BCPP (23.8 μg/g creatinine) was notably higher than the adult male general population (0.159 μg/g creatinine, p < 0.001). Urinary BCPP GM concentration increased significantly from Pre-shift Day 1 to Post-shift Day 2 for sprayers (p = 0.013) and helpers (p = 0.009). Among bulk samples, cured open-cell foam had a TCPP GM concentration of 9.23% by weight while closed-cell foam was 1.68%. Overall, post-shift BCPP urine concentrations were observed to be associated with TCPP air and hand wipe concentrations, as well as job position (sprayer vs. helper). Spray polyurethane foam workers should wear personal protective equipment including air-supplied respirators, coveralls, and gloves during application.

Salivary Cortisol Concentrations, Grit, and the Effect of Time.

Stress is a common experience in the emergency department (ED) and is a balance of personal capabilities versus demands. Residency training is meant to improve individuals' capabilities and therefore may attenuate an individual's stress response. Grit is a personality trait that may attenuate stress in individuals. In this study we explore the relationship between time of year, postshift salivary cortisol concentrations, and the influence of grit among attendings and residents in an academic ED. Thirty-nine residents and 17 attendings were enrolled and followed for two academic years at an urban academic medical center. Postwork salivary cortisol samples were collected quarterly, and Duckworth 12-point Grit Scales were administered annually. Data from the relative quarters of the first and second years were combined, and the results were analyzed using descriptive statistics and generalized estimating equations. We analyzed 216 cortisol samples and 87 grit scores over 2 academic years. Between the first and fourth quarters of the academic year, the percentage of subjects with a detectable postshift cortisol sample decreased from 47.6% (30 of 62) to 18.4% (9 of 49). In the fourth academic quarter compared to the first, the odds that an individual had a detectable cortisol were significantly lower overall (odds ratio[OR] = 0.25, 95% confidence interval [CI]= 0.10 to 0.59, p=0.01), including the subset of only trainees (OR= 0.26, 95% CI= 0.07 to 0.88, p=0.01), and adjusting for grit did not meaningfully change the ORs. Over the course of the academic year, the odds that an individual's postshift salivary cortisol concentration will be above detectable concentration significantly decrease over time, and this relationship is not confounded by grit.

Detection and identification of engineered nanoparticles in exhaled breath condensate, blood serum, and urine of occupationally exposed subjects

The use of nanotechnology and the fields of application of nanomaterials are growing vastly, but the negative health effects on the exposed employees are not well studied. The standardized methods of monitoring of occupational exposure are still absent. The task of occupational physicians is to find the ways of evaluation of potential risks of exposure to engineered nanoparticles and to determine the biomarkers for early diagnostics and prevention of occupational diseases. The aim of our study was to detect and identify engineered nanoparticles in biological samples received from occupationally exposed subjects and to evaluate the association of findings with the results of external aerosol measurements on the workplace. The study cohort consisted of two groups of subjects. The first group was exposed to engineered nanoparticles containing mainly iron, manganese, and carbon compounds; the second group was exposed to the nanoparticles containing copper oxide. The post-shift biological samples (urine, blood serum, and exhaled breath condensate) were collected. The analysis was performed by transmission electron microscopy and energy-dispersive spectroscopy. The nanoparticles were detected in all the biological samples. The most common identified chemical elements were the biogenic ones (carbon, potassium, chlorine, oxygen), but the nanoparticles containing metals were identified in EBC, blood, and urine as well (gold, silver, copper, lanthanum, cerium, and tantalum). Our results demonstrate the possibility of detection of occupational exposure to the engineered nanoparticles in human biological fluids. Further studies are necessary to compare the pre-shift and post-shift burden of samples with engineered nanoparticles and to determine the magnitude of occupational exposure during the shift.

Intrusion of chlorinated hydrocarbons and their degradation products from contaminated soil. Measurement of indoor air quality and biomonitoring by analysis of end-exhaled air

A historic soil contamination of chlorinated hydrocarbons from a former dry cleaning shop caused intrusion of vapors into a building currently used as bookshop. The aim of this study was to determine the indoor air quality and the uptake of soil contaminants and their degradation products. Samples of indoor air were collected over one week in the warm and one week in the cold season. Pre-shift and post-shift samples of end-exhaled air were collected from two employees. Chlorinated hydrocarbons were analyzed in indoor air and exhaled air samples using thermal desorption gas chromatography mass spectrometry (TD-GC–MS). Tetrachloroethylene (PER), and its degradation products trichloroethylene (TRI), 1,1-dichloroethylene (1,1-DCE), 1,2-cis-dichloroethylene (1,2-cis-DCE), 1,2-trans-dichloroethylene (1,2-trans-DCE), methylene chloride (MC) and vinyl chloride (VC) were determined in ambient air. PER was the prime contaminant with a week average (±sd) of 805.2 ± 598.6 μg/m3 in June 2016 and 1031 ± 499.3 μg/m3 in December 2017. MC, 1,2-cis-DCE and TRI were detected at concentrations below 2.3 μg/m3. 1,1-DCE and VC were not detected. In exhaled air PER, 1,1-DCE, and MC were detected in both June and December, whereas TRI, 1,2-cis-DCE and 1,2-trans-DCE were only detected on one or two days in the cold season. VC was not detected in exhaled air. For PER, the mean concentrations (±sd) in end-exhaled air increased from a five days (Mon-Fri) average pre-shift value of 22.2 ± 8.0 to a post-shift value of 52.6 ± 15.5 ng/L in the male shop owner (p < 0.01) and in the female cashier these values were 26.0 ± 3.6 and 63.6 ± 12.7 ng/L, respectively (p < 0.01). Intrusion of chlorinated soil contaminants resulted in contamination of indoor air above the current accepted indoor air level for PER of 250 μg/m3. For PER in end-exhaled air an accumulation over the workweek was not observed.

Deep Airway Inflammation and Respiratory Disorders in Nanocomposite Workers.

Thousands of researchers and workers worldwide are employed in nanocomposites manufacturing, yet little is known about their respiratory health. Aerosol exposures were characterized using real time and integrated instruments. Aerosol mass concentration ranged from 0.120 mg/m3 to 1.840 mg/m3 during nanocomposite machining processes; median particle number concentration ranged from 4.8 × 104 to 5.4 × 105 particles/cm3. The proportion of nanoparticles varied by process from 40 to 95%. Twenty employees, working in nanocomposite materials research were examined pre-shift and post-shift using spirometry and fractional exhaled nitric oxide (FeNO) in parallel with 21 controls. Pro-inflammatory leukotrienes (LT) type B4, C4, D4, and E4; tumor necrosis factor (TNF); interleukins; and anti-inflammatory lipoxins (LXA4 and LXB4) were analyzed in their exhaled breath condensate (EBC). Chronic bronchitis was present in 20% of researchers, but not in controls. A significant decrease in forced expiratory volume in 1 s (FEV1) and FEV1/forced vital capacity (FVC) was found in researchers post-shift (p ˂ 0.05). Post-shift EBC samples were higher for TNF (p ˂ 0.001), LTB4 (p ˂ 0.001), and LTE4 (p ˂ 0.01) compared with controls. Nanocomposites production was associated with LTB4 (p ˂ 0.001), LTE4 (p ˂ 0.05), and TNF (p ˂ 0.001), in addition to pre-shift LTD4 and LXB4 (both p ˂ 0.05). Spirometry documented minor, but significant, post-shift lung impairment. TNF and LTB4 were the most robust markers of biological effects. Proper ventilation and respiratory protection are required during nanocomposites processing.