Hepatic metabolism of heme in rats after exposure to benzene,gasoline and kerosene

-Aminolevulinic acid (ALA) synthetase, -ALA dehydratase and heme oxygenase activities were studied in the liver of albino rats, 3 and 20 h after i.p. administration of benzene, gasoline, and kerosene. -ALA synthetase activity was increased markedly after benzene administration, while gasoline and kerosene treated groups showed decreased enzyme activity. Inhibition of -ALA dehydratase activity was observed in all three groups, but heme oxygenase activity was unchanged.     

Pharmacokinetically based risk assessment of workplace exposure to benzene

Cancer risk from exposure to benzene for a working lifetime was estimated from data obtained in studies with rodents. Cancers of the Zymbal gland and the blood-forming system were selected as endpoints for the assessment because of their consistent occurrence. The combined metabolites were judged from toxicological data to be the best representative of the reactive agent. Because of similarity in the percentages of lifetime exposed in the rodent studies and in the occupational setting, the amount metabolized/day as a result of exposures 5 days a week for a lifetime was judged to be an appropriate dose paradigm for this assessment. Derived Michaelis-Menton constants were used to convert the doses of combined metabolites from the pharmacokinetic studies to the doses used in the bioassays. Scaling across species was based on allometric relationships. Experimental data were used to scale doses across species with body weight ratios raised to the exponents of 0.74 for the inhalation route and 1.0 for the oral route. The occupational lifetime cancer risk estimated from rodent data was 6 to 14 cases/1000 workers, which is consistent with the 9.5 to 174 leukemia cases/1000 estimated by others from epidemiological data. Implications of these estimates and uncertainties associated with making them are discussed.     

Comparison of different exposure assessment methods to estimate the long-term dietary exposure to dioxins and ochratoxin A

Long-term exposures to dioxins (PCCD/F and dioxin-like PCBs) and ochratoxin A were calculated using food consumption data of the European concise database combined with concentration data of the Netherlands (NL) using a deterministic approach. To refine these assessments, exposures were also calculated using three long-term exposure models, observed individual means (OIM), Iowa State University Foods (ISUF), and betabinomial-normal (BBN) models, combined with individual food consumption data of NL. BBN and ISUF correct the variation in long-term exposure for the within-person variation, whereas OIM calculates the mean exposure over the days in the food consumption survey. Exposures obtained with the concise database were highest, and those obtained with OIM higher than with BBN and ISUF. Contribution of the major sources of exposure differed between the concise database and the three models. Given the constraints of the concise database, exposures obtained with this database should be interpreted as a first tier assessment. Preferably, refined assessments using models that correct the variation in long-term exposure for the within-person variation combined with individual food consumption data and national concentration data should be used to assess the long-term exposure. We recommend the use of BBN since it can model exposure distributions that depend on covariates.     

Risk assessment and management of occupational exposure to pesticides.

Occupational exposure to pesticides in agriculture and public health applications may cause acute and long-term health effects. Prevention of adverse effects in the users requires actions to be undertaken in the pre-marketing and post-marketing phase of these products. The pre-marketing preventive actions are primary responsibility of industry and the public administration. Admission of pesticide use (registration) is carried out by considering the toxicological properties of each pesticide (hazard identification), determining the dose-response relationship (NOEL identification), assessing or predicting the exposure level in the various scenarios of their use, and characterising the risk. The decision about admission takes into consideration the balance between risks and benefits. The post-marketing preventive activities consist of the promotion of a proper risk management at the workplace. Such a management includes the risk assessment of the specific conditions of use, the adoption of proper work practices, and the health surveillance of the workers. Each country should develop an adequate National Plan for Prevention of Pesticide Risk which allocates different roles and tasks at the central, regional and local level.     

Evaluation of quantification methods of occupational endotoxin exposure

Endotoxin has been identified as important component of organic-dust exposure and is suspected as main cause of work-related adverse health effects in dusty areas. Although the determination of endotoxin levels by using the Limulus amoebocyte lysate (LAL) assay is internationally accepted, reliability and variation of values measured with this test remain a point of discussion. Therefore, the purpose of the study was to determine the influence of different parameters on endotoxin activity measured in airborne samples. This study thus analyzed: (a) dust filter extraction procedures, (b) storage of samples, (c) usage of different commercially available LAL assays, and (d) results of the whole blood assay (WBA) compared to the LAL test. Using a parallel sampler, 120 filters were loaded with dust at 4 different occupational settings and extracted in 2 labs using a standardized protocol. Parameters like Tween in the extraction medium, extraction volume, centrifugation speed, and material of tubes used for extraction were tested. The LAL test and the WBA were able to determine the differences in dust load of filters obtained from the settings investigated. In addition, results varied significantly with modifications in extraction procedures. Using Tween for filter extraction mainly influenced the resulting endotoxin activity. In addition, LAL test differences according to manufacturer of LAL test, extraction volume, and whether the samples are freshly processed or frozen also resulted in significant variations in the endotoxin levels. In conclusion, a reliable assessment of exposure to endotoxin activity is only possible if standard operation procedures (SOPs) for sampling and determination are established.     

Ambient air levels and occupational exposure to benzene,toluene, and xylenes in northwestern Italy

The purpose of this study was to determine benzene, toluene, and xylenes air pollution in two cities in Italy (Biella and Torino) having different traffic intesities and to investigate whether new environmental conditions occurred consequent to the changes of gasoline composition in Europe during the last 20 yr. Furthermore, three types of urban occupational exposure (petrol pump attendants, traffic policemen, and municipal employees) to the same hydrocarbons were compared to verify three different expected levels of exposure. Results in Biella demonstrate a direct relationship between traffic density and level of human exposure to these pollutants. Air concentrations for benzene were 2.3 micrograms/m3 in a suburban area having low traffic and 10.3 micrograms/m3 in the central area having high traffic. The comparison to trend analysis recently carried out in Torino indicates it is possible to improve the situation in the central area of Biella by adopting the same traffic limitations imposed in Torino. Personal sampling devices demonstrated that only the petrol pump attendants show, by means of a multivariate analysis, statistically significant higher levels of benzene compared to the other two professional categories, in both winter and summer. Values found in the present study for petrol pump attendants were around 1 mg/m3. Environmental and occupational exposure to benzene, toluene, and xylenes could be largely lowered by adopting preventive measures including traffic restrictions, the reduction of aromatic chemical content in gasoline, and the recovery of gasoline vapors at petrol pump stations.     

The role of exposure reconstruction in occupational human health risk assessment: Current methods and a recommended framework

Exposure reconstruction for substances of interest to human health is a process that has been used, with various levels of sophistication, as far back as the 1930s. The importance of robust and high-quality exposure reconstruction has been recognized by many researchers. It has been noted that misclassification of reconstructed exposures is relatively common and can result in potentially significant effects on the conclusions of a human health risk assessment or epidemiology study. In this analysis, a review of the key exposure reconstruction approaches described in over 400 papers in the peer-reviewed literature is presented. These approaches have been critically evaluated and classified according to quantitative, semiquantitative, and qualitative approaches. Our analysis indicates that much can still be done to improve the overall quality and consistency of exposure reconstructions and that a systematic framework would help to standardize the exposure reconstruction process in the future. The seven recommended steps in the exposure reconstruction process include identifying the goals of the reconstruction, organizing and ranking the available data, identifying key data gaps, selecting the best information sources and methodology for the reconstruction, incorporating probabilistic methods into the reconstruction, conducting an uncertainty analysis, and validating the results of the reconstruction. Influential emerging techniques, such as Bayesian data analysis, are highlighted. Important issues that will likely influence the conduct of exposure reconstruction into the future include improving statistical analysis methods, addressing the issue of chemical mixtures, evaluating aggregate exposures, and ensuring transparency with respect to variability and uncertainty in the reconstruction effort.     

Co-exposure to gasoline vapor decreases benzene metabolism in Fischer-344 rats.

The metabolic interactions of benzene and gasoline vapor were investigated in male Fischer-344 rats. A closed chamber gas-uptake exposure system was used to obtain inhalation uptake curves for benzene alone and benzene in the presence of gasoline vapor. Exposure to benzene as a component of gasoline vapor resulted in a decrease of benzene metabolism. A physiologically based pharmacokinetic model of benzene metabolism was used to quantitatively determine the extent of the inhibitory effect of gasoline vapor on benzene metabolism. This observed inhibitory effect cannot be accounted for by the presence of toluene in gasoline vapor.     

Dermal absorption of benzene in occupational settings: Estimating flux and applications for risk assessment

There is growing emphasis in the United States and Europe regarding the quantification of dermal exposures to chemical mixtures and other substances. In this paper, we determine the dermal flux of benzene in neat form, in organic solvents, and in aqueous solutions based on a critical review and analysis of the published literature, and discuss appropriate applications for using benzene dermal absorption data in occupational risk assessment. As part of this effort, we synthesize and analyze data for 77 experimental results taken from 16 studies of benzene skin absorption. We also assess the chemical activity of benzene in simple hydrocarbon solvent mixtures using a thermodynamic modeling software tool. Based on the collective human in vivo, human in vitro, and animal in vitro data sets, we find that the steady-state dermal flux for neat benzene (and benzene-saturated aqueous solutions) ranges from 0.2 to 0.4?mg/(cm²?h). Observed outlier values for some of the animal in vivo data sets are possibly due to the use of test species that have more permeable skin than humans or study conditions that resulted in damage to the skin barrier. Because relatively few dermal absorption studies have been conducted on benzene-containing organic solvents, and available test results may be influenced by study design or vehicle effects, it is not possible to use these data to quantify the dermal flux of benzene for other types of solvent mixtures. However, depending on the application, we describe several potential approaches that can be used to derive a rough approximation of the steady-state benzene dermal flux for these mixtures. Important limitations with respect to quantifying and evaluating the significance of dermal exposures to benzene in occupational settings include a lack of data on (1) factors that affect the dermal uptake of benzene, (2) the dermal flux of benzene for different organic solvent mixtures, (3) meaningful metrics for evaluating the dermal uptake of benzene, (4) steady-state versus non-steady-state dermal flux values for benzene, (5) the effect of skin damage on the dermal flux of benzene, (6) standardized test methods for estimating the dermal flux of benzene, and (7) robust estimates of the evaporation rate of benzene from different liquid vehicles.     

Dermal absorption of benzene in occupational settings: estimating flux and applications for risk assessment

There is growing emphasis in the United States and Europe regarding the quantification of dermal exposures to chemical mixtures and other substances. In this paper, we determine the dermal flux of benzene in neat form, in organic solvents, and in aqueous solutions based on a critical review and analysis of the published literature, and discuss appropriate applications for using benzene dermal absorption data in occupational risk assessment. As part of this effort, we synthesize and analyze data for 77 experimental results taken from 16 studies of benzene skin absorption. We also assess the chemical activity of benzene in simple hydrocarbon solvent mixtures using a thermodynamic modeling software tool. Based on the collective human in vivo, human in vitro, and animal in vitro data sets, we find that the steady-state dermal flux for neat benzene (and benzene-saturated aqueous solutions) ranges from 0.2 to 0.4 mg/(cm2·h). Observed outlier values for some of the animal in vivo data sets are possibly due to the use of test species that have more permeable skin than humans or study conditions that resulted in damage to the skin barrier. Because relatively few dermal absorption studies have been conducted on benzene-containing organic solvents, and available test results may be influenced by study design or vehicle effects, it is not possible to use these data to quantify the dermal flux of benzene for other types of solvent mixtures. However, depending on the application, we describe several potential approaches that can be used to derive a rough approximation of the steady-state benzene dermal flux for these mixtures. Important limitations with respect to quantifying and evaluating the significance of dermal exposures to benzene in occupational settings include a lack of data on (1) factors that affect the dermal uptake of benzene, (2) the dermal flux of benzene for different organic solvent mixtures, (3) meaningful metrics for evaluating the dermal uptake of benzene, (4) steady-state versus non-steady-state dermal flux values for benzene, (5) the effect of skin damage on the dermal flux of benzene, (6) standardized test methods for estimating the dermal flux of benzene, and (7) robust estimates of the evaporation rate of benzene from different liquid vehicles.     

Derivation of occupational exposure limits: Differences in methods and protection levels

Frameworks for deriving occupational exposure limits (OELs) and OEL-analogue values (such as derived-no-effect levels [DNELs]) in various regulatory areas in the EU and at national level in Germany were analysed. Reasons for differences between frameworks and possible means of improving transparency and harmonisation were identified. Differences between assessment factors used for deriving exposure limits proved to be one important reason for diverging numerical values. Distributions for exposure time, interspecies and intraspecies extrapolation were combined by probabilistic methods and compared with default values of assessment factors used in the various OEL frameworks in order to investigate protection levels. In a subchronic inhalation study showing local effects in the respiratory tract, the probability that assessment factors were sufficiently high to protect 99% and 95% of the target population (workers) from adverse effects varied considerably from 9% to 71% and 17% to 87%, respectively, between the frameworks. All steps of the derivation process, including the uncertainty associated with the point of departure (POD), were further analysed with two examples of full probabilistic assessments. It is proposed that benchmark modelling should be the method of choice for deriving PODs and that all OEL frameworks should provide detailed guidance documents and clearly define their protection goals by stating the proportion of the exposed population the OEL aims to cover and the probability with which they intend to provide protection from adverse effects. Harmonisation can be achieved by agreeing on the way to perform the methodological steps for deriving OELs and on common protection goals.     

Toxicity and occupational exposure assessment for Fischer-Tropsch synthetic paraffinic kerosene

Fischer-Tropsch (FT) Synthetic Paraffinic Kerosene (SPK) jet fuel is a synthetic organic mixture intended to augment petroleum-derived JP-8 jet fuel use by the U.S. armed forces. The FT SPK testing program goal was to develop a comparative toxicity database with petroleum-derived jet fuels that may be used to calculate an occupational exposure limit (OEL). Toxicity investigations included the dermal irritation test (FT vs. JP-8 vs. 50:50 blend), 2 in vitro genotoxicity tests, acute inhalation study, short-term (2-week) inhalation range finder study with measurement of bone marrow micronuclei, 90-day inhalation toxicity, and sensory irritation assay. Dermal irritation was slight to moderate. All genotoxicity studies were negative. An acute inhalation study with F344 rats exposed at 2000 mg/m³ for 4 hr resulted in no abnormal clinical observations. Based on a 2-week range-finder, F344 rats were exposed for 6 hr per day, 5 days per week, for 90 days to an aerosol-vapor mixture of FT SPK jet fuel (0, 200, 700 or 2000 mg/m³). Effects on the nasal cavities were minimal (700 mg/m³) to mild (2000 mg/m³); only high exposure produced multifocal inflammatory cell infiltration in rat lungs (both genders). The RD₅₀ (50% respiratory rate depression) value for the sensory irritation assay, calculated to be 10,939 mg/m^3, indicated the FT SPK fuel is less irritating than JP-8. Based upon the proposed use as a 50:50 blend with JP-8, a FT SPK jet fuel OEL is recommended at 200 mg/m³ vapor and 5 mg/m³ aerosol, in concurrence with the current JP-8 OEL.     

Vinyl chloride: an assessment of the risk of occupational exposure

There is little doubt that exposure to high levels of VCM as a consequence of occupation can result in an increased incidence of ASL. A review of 20 epidemiological studies involving about 45,000 workers occupationally exposed to VCM showed that neoplasms of the liver showed an increase in incidence in the majority of studies. For brain cancer the association between exposure to VCM and an increased incidence was less clear because of the lower relative risk. Neoplasms of the respiratory tract, digestive system, lymphatic and haemopoietic system, buccal cavity, and pharynx, cardiovascular system and colon/stomach were reported to show an increased incidence in one or more studies, but to show no increase, or in some cases a decrease, in incidence in other studies. In view of the increased incidence of breast neoplasms in rodents exposed to VCM, the studies of Chaizze et al. (1980), who did not confirm these findings in humans, are of importance. The register of ASL cases now contains records of 99 persons with confirmed ASL and occupational exposure to VCM. The average latent period between first exposure to VCM and death from ASL is 21.9 years. The majority of cases occurred in autoclave workers, who are recognized as having been exposed to extremely high levels. Although precise estimates of exposure are not available for the periods of most interest, the pattern of cases roughly suggests that extremely high exposures were necessary for the induction of ASL. For example, ASL cases tended to occur in larger numbers in some plants than in others, a finding that can be explained most easily by differences in exposure patterns. There is an extensive series of animal studies on the carcinogenicity of VCM. Some of these precede the epidemiological studies confirming the association between VCM exposure and ASL in man. ASL and neoplasms of a number of other organs have been induced in laboratory rodents by VCM. Estimation of the exposure levels likely to cause a lifetime risk of ASL of 10(-6) on the basis of these data give extremely low levels (down to 3.9 X 10(-7) ppb) which appear to be unrealistic estimates for man. Part of the reason for this is that laboratory studies have shown that VCM is metabolized in the liver (and elsewhere in the body) to the reactive metabolites chloroethylene oxide and chloroacetaldehyde. The rate of conversion is limited at high levels of exposure giving inaccurate estimates of the slope of the dose-response relationship.(ABSTRACT TRUNCATED AT 400 WORDS)     

Comparison of inflammatory elements in nasal lavage and induced sputum following occupational exposure to moldy-building microbes

Inflammatory processes in the nasal air passages may reflect corresponding processes in the lower airways due to the similarities in histology of nasal mucosa and bronchi. The objective of the current study was to determine whether the levels of inflammatory markers in nasal lavage fluid could be used as predictors of lower respiratory tract inflammation after exposure to microbes in indoor air of moisture-damaged buildings. Differential cell count, immunochemically measured concentrations of proinflammatory cytokines (Interleukins [IL] IL-1, IL-4, IL-6, and tumor necrosis factor alpha [TNFalpha]) and nitric oxide (NO), assessed as nitrite, were analyzed from nasal lavage (NL) and induced sputum (IS) samples of the occupants (n = 60) working in moisture-damaged and reference school buildings. The measurements of inflammation markers in NL and IS sample pairs, collected on the same day, were compared. Although the levels of NO (p =.026) and IL-4 (p =.014) in NL predicted their levels in IS in a statistically significant manner, their predictive values (6.9% and 7.8%, respectively) were low. There was no significant correlation between the concentrations of the studied proinflammatory cytokines or differential cell counts in NL and IS samples. Our results indicate that measurement of inflammatory mediators in NL is not per se a reliable method to evaluate the inflammatory status of the lower airways after exposure to indoor air pollutants of moisture damaged building. It is possible that NL is a more sensitive indicator of direct exposure to different irritants in inhaled air than is IS. This may be a reflection of the role of nasal mucosa as the primary physicochemical barrier to inhaled air.     

Use of primary blood cells for the assessment of exposure to occupational genotoxicants in human biomonitoring studies

The Comet assay is an often used approach for the assessment of genetic damage in primary cells of exposed populations. In the majority of these studies lymphocytes are used. Therefore, we reviewed human biomonitoring studies of occupational exposure using the Comet assay with lymphocytes. We also tried to elucidate the strengths of the studies, which were that (i) data could be obtained in a fast and cost-effective manner, (ii) the ease at which these cells can be collected and (iii) a remarkable concordance between Comet assay and cytogenetic assays. However, the analysis also revealed some shortcomings: (i) the low number of study participants, (ii) the bias in the distribution of gender, (iii) lack of qualitative and quantitative exposure data, (iv) omission to consider differences in physical activity and diet between control and exposed groups, (v) lack of uniformity in the Comet assay procedures, and (vi) controversy in the sensitivity of Comet assay since it picked up DNA damage caused by agents which were found to be weak genotoxicants or non-genotoxicants in other tests, but gave inconsistent results with known mutagens/carcinogens such as cigarette smoke.     

手术室骨科专科护士职业暴露的风险管理与防护

目的探讨手术室骨科专科护士职业暴露的风险管理与防护。方法采集2009年1月-2009年125480例骨科关节置换手术护士职业暴露的例数,进行风险因素评估,制定护理对策,预警干预手术室护士职业暴露的发生。结果通过对480例骨科关节置换手术骨科专科护士职业暴露发生例数分析,其中对照组发生职业暴露22例,职业暴露发生率为8．8％;干预组5例,职业暴露发生率为2．2％,两组间的差异有统计学意义（P〈0．01）。结论通过风险因素评估,干预手术室护士职业暴露的发生,降低手术护士职业暴露发生率。     

Drugs hazardous to healthcare workers. Evaluation of methods for monitoring occupational exposure to cytostatic drugs.

We review the literature concerning possible health risks for individuals (e.g. healthcare workers and pharmaceutical plant employees) occupationally exposed to cytostatic drugs. Cytostatic drugs possess toxic properties and may therefore cause mutagenic, carcinogenic and teratogenic effects. Hence, individuals handling these drugs in the course of their employment may face health risks. For this reason, it is important to monitor occupational exposure to these drugs. An overview of exposure monitoring methods is presented and their value is discussed. Most studies involve nonselective methods for biological monitoring and biological effect monitoring, such as the urinary mutagenicity assay and analysis of chromosomal aberrations and sister-chromatid exchanges in peripheral blood lymphocytes. The disadvantages of these biological methods are that their sensitivity is low and it cannot be proved beyond any doubt that the results found were caused by occupational exposure to cytostatic drugs. For occupational health services it is important to have sensitive and specific methods for monitoring exposure to cytostatic drugs. One of the most promising methods seems to be the determination of cyclophosphamide in urine using gas chromatography-tandem mass spectrometry. Several studies have demonstrated exposure to cyclophosphamide and other cytostatic drugs, even when protective measures were taken and safety guidelines were followed. To estimate the magnitude of any health effects arising from this exposure, we calculated the risk of cancer due to occupational exposure to cyclophosphamide on the basis of available human and animal dose-response data and the amounts of cyclophosphamide found in urine. The initial results show an extra cancer risk for pharmacy technicians and nurses.     

Extensive changes to occupational exposure limits in Korea

Occupational exposure limits (OELs) are used as an important tool to protect workers from adverse chemical exposures and its detrimental effects on their health. The Ministry of Labor (MOL) can establish and publish OELs based on the Industrial Safety and Health Act in Korea. The first set of OELs was announced by the MOL in 1986. At that time, it was identical to the Threshold Limit Values of the American Conference of Governmental Industrial Hygienists. Until 2006, none the first OELs except for those of three chemicals (asbestos, benzene, and 2-bromopropane) were updated during the last twenty years. The Hazardous Agents Review Committee established under the MOL selected 126 chemicals from 698 chemicals covered by OELs using several criteria. From 2005 to 2006, the MOL provided research funds for academic institutions and toxicological laboratories to gather the evidence documenting the need to revise the outdated OELs. Finally, the MOL notified the revised OELs for 126 chemicals from 2007 to 2008. The revised OELs of 58 substances from among these chemicals were lowered to equal or less than half the value of the original OELs. This is the most substantial change in the history of OEL revisions in Korea.     

Comparison and evaluation of urinary biomarkers for occupational exposure to spray adhesives containing 1-bromopropane

Three metabolites of 1-bromopropane (1-BP) were measured in urine samples collected from 30 workers exposed to 1-BP at two facilities making furniture seat cushions and evaluated for use as biomarkers of exposure. The mercapturic acid metabolite, N-acetyl-S-(n-propyl)-l-cysteine (AcPrCys), 3-bromopropionic acid (3-BPA), and bromide ion levels (Br^?) were quantitated for this evaluation. The high exposure group consisted of 13 workers employed as adhesive sprayers who assembled foam cushions using 1-BP containing spray adhesives and the low exposure group consisted of 17 non-sprayers, who worked in various jobs without spraying adhesives. All workers’ urine voids were collected over the same 48 h period at work, and at home before bedtime, and upon awakening. Urinary AcPrCys and Br^? levels were elevated in the sprayers compared to that of non-sprayers. Following HPLC-MS/MS analysis of mercapturic acid metabolite levels, 50 urine samples having the highest levels of AcPrCys were analyzed for 3-BPA. No 3-BPA was detected in any of the samples. The data collected from this study demonstrate that AcPrCys and Br^? are effective biomarkers of 1-BP exposure, but 3-BPA is not.     

Comparison and evaluation of urinary biomarkers for occupational exposure to spray adhesives containing 1-bromopropane

Three metabolites of 1-bromopropane (1-BP) were measured in urine samples collected from 30 workers exposed to 1-BP at two facilities making furniture seat cushions and evaluated for use as biomarkers of exposure. The mercapturic acid metabolite, N-acetyl-S-(n-propyl)-l-cysteine (AcPrCys), 3-bromopropionic acid (3-BPA), and bromide ion levels (Br(-)) were quantitated for this evaluation. The high exposure group consisted of 13 workers employed as adhesive sprayers who assembled foam cushions using 1-BP containing spray adhesives and the low exposure group consisted of 17 non-sprayers, who worked in various jobs without spraying adhesives. All workers' urine voids were collected over the same 48 h period at work, and at home before bedtime, and upon awakening. Urinary AcPrCys and Br(-) levels were elevated in the sprayers compared to that of non-sprayers. Following HPLC-MS/MS analysis of mercapturic acid metabolite levels, 50 urine samples having the highest levels of AcPrCys were analyzed for 3-BPA. No 3-BPA was detected in any of the samples. The data collected from this study demonstrate that AcPrCys and Br(-) are effective biomarkers of 1-BP exposure, but 3-BPA is not.