scholarly journals Ethylene Oxide Exposure in U.S. Populations Residing Near Sterilization and Other Industrial Facilities: Context Based on Endogenous and Total Equivalent Concentration Exposures

2021 ◽  
Vol 18 (2) ◽  
pp. 607
Author(s):  
Patrick J. Sheehan ◽  
Ryan C. Lewis ◽  
Christopher R. Kirman ◽  
Heather N. Watson ◽  
Eric D. Winegar ◽  
...  
Keyword(s):  
Cancer Risk ◽  
Ethylene Oxide ◽  
Environmental Protection Agency ◽  
Cancer Risk Assessment ◽  
Exposure Concentration ◽  
Increase Cancer Risk ◽  
Total Exposure ◽  
Industrial Facilities ◽  
Equivalent Concentration ◽  
Current Risk

Given ubiquitous human exposure to ethylene oxide (EO), regardless of occupation or geography, the current risk-specific concentrations (RSCs: 0.0001–0.01 ppb) from the U.S. Environmental Protection Agency (EPA) cancer risk assessment for EO are not useful metrics for managing EO exposures to the general U.S. population. The magnitude of the RSCs for EO are so low, relative to typical endogenous equivalent metabolic concentrations (1.1–5.5 ppb) that contribute ~93% of total exposure, that the RSCs provide little utility in identifying excess environmental exposures that might increase cancer risk. EO monitoring data collected in the vicinity of eight EO-emitting facilities and corresponding background locations were used to characterize potential excess exogenous concentrations. Both 50th and 90th percentile exogenous exposure concentrations were combined with the 50th percentile endogenous exposure concentration for the nonsmoking population, and then compared to percentiles of total equivalent concentration for this population. No potential total exposure concentration for these local populations exceeded the normal total equivalent concentration 95th percentile, indicating that excess facility-related exposures are unlikely to require additional management to protect public health.

Cancer and non-cancer health risk assessment of occupational exposure to 1,3-butadiene in a petrochemical plant in Iran

2020 ◽  
Vol 36 (12) ◽  
pp. 960-970
Author(s):  
Mohsen Sadeghi-Yarandi ◽  
Ali Karimi ◽  
Vahid Ahmadi ◽  
Ali Asghar Sajedian ◽  
Ahmad Soltanzadeh ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Occupational Exposure ◽  
Cancer Risk ◽  
Environmental Protection Agency ◽  
Hazard Quotient ◽  
The United States ◽  
Cancer Risk Assessment ◽  
Risk Level ◽  
Average Lifetime ◽  
Petrochemical Plant

1,3-Butadiene is classified as carcinogenic to humans by inhalation. This study aimed to assess cancer and non-cancer risk following occupational exposure to 1,3-butadiene. This cross-sectional study was conducted in a petrochemical plant producing acrylonitrile butadiene styrene copolymer in Iran. Occupational exposure to 1,3-butadiene was measured according to the National Institute for Occupational Safety and Health 1024 method. Cancer and non-cancer risk assessment were performed according to the United States Environmental Protection Agency method. The average occupational exposure to 1,3-butadiene during work shifts among all participants was 560.82 ± 811.36 µg m−3. The average lifetime cancer risk (LCR) in the present study was 2.71 × 10−3; 82.2% of all exposed workers were within the definite carcinogenic risk level. Also, the mean non-cancer risk (hazard quotient (HQ)) among all participants was 10.82 ± 14.76. The highest LCR and HQ were observed in the safety and fire-fighting station workers with values of 7.75 × 10−3 and 36.57, respectively. The findings revealed that values of carcinogenic and noncarcinogenic risk in the majority of participants were within the definitive and unacceptable risk levels. Therefore, corrective measures are necessary to protect these workers from non-cancer and cancer risks from 1,3-butadiene exposure.

scholarly journals Ethylene Oxide Exposure Attribution and Emissions Quantification Based on Ambient Air Measurements near a Sterilization Facility

2019 ◽  
Vol 17 (1) ◽  
pp. 42 ◽  
Author(s):  
Eduardo P. Olaguer ◽  
Amy Robinson ◽  
Susan Kilmer ◽  
James Haywood ◽  
Doreen Lehner
Keyword(s):  
Cancer Risk ◽  
Ethylene Oxide ◽  
Environmental Protection Agency ◽  
Background Level ◽  
Ambient Air ◽  
Background Concentration ◽  
Second Phase ◽  
Field Investigations ◽  
Simple Mass ◽  
Two Phases

Ethylene oxide (EtO) is a known carcinogen and mutagen associated with increased incidence of breast and blood cancers. The largest medical sterilization facility in Michigan had been assessed by the U.S. Environmental Protection Agency as imposing an additional cancer risk greater than one in one thousand in nearby neighborhoods. This prompted the Michigan Department of Environmental Quality (now referred to as the Department of Environment, Great Lakes, and Energy) to conduct an air quality modeling study of the ambient EtO impacts of the sterilization facility, followed by 24 h Summa canister sampling and TO-15 analysis in two phases. Inverse modeling of the measured 24 h EtO concentrations during the second phase yielded estimates of 594 lbs/year for the facility’s total emissions of EtO and 0.247 µg/m3 for the urban background concentration. The inverse-modeled emissions are similar to reported emissions by the facility operator based on indoor air measurements and simple mass balance assumptions, while the inferred background concentration agrees with estimates from other field investigations. The estimated peak 24 h exposure to EtO caused by the sterilization facility in nearby neighborhoods was 1.83 μg/m3 above the background level, corresponding to an additional cancer risk of approximately one in one hundred, if assumed to represent annual mean exposure.

scholarly journals Reevaluation of Historical Exposures to Ethylene Oxide Among U.S. Sterilization Workers in the National Institute of Occupational Safety and Health (NIOSH) Study Cohort

2019 ◽  
Vol 16 (10) ◽  
pp. 1738 ◽  
Author(s):  
Kenneth T. Bogen ◽  
Patrick J. Sheehan ◽  
Ciriaco Valdez-Flores ◽  
Abby A. Li
Keyword(s):  
Cancer Risk ◽  
Ethylene Oxide ◽  
Environmental Protection Agency ◽  
Occupational Safety ◽  
Weighted Average ◽  
Occupational Safety And Health ◽  
Study Cohort ◽  
Statistical Regression ◽  
Trend Prediction ◽  
Safety And Health

The 2016 U.S. Environmental Protection Agency (EPA) Integrated Risk Information System (IRIS) assessment for ethylene oxide (EO) estimated a 10−6 increased inhalation cancer risk of 0.1 parts per trillion, based on National Institute of Occupational Safety and Health (NIOSH) epidemiology studies of sterilization facility workers exposed to EO between 1938 and 1986. The worker exposure estimates were based on a NIOSH statistical regression (NSR) model “validated” with EO levels measured after 1978. Between 1938 and 1978, when EO data was unavailable, the NSR model predicts exposures lowest in 1938 increasing to peak levels in 1978. That increasing EO concentration trend arose, in part, because engineering/industrial-hygiene (E/IH) factors associated with evolving EO-sterilization equipment and operations before 1978 were not properly considered in the NSR model. To test the NSR model trend prediction, a new E/IH-based model was developed using historical data on EO kill concentrations, EO residue levels in sterilized materials, post-wash EO concentrations in a sterilization chamber, and information on facility characteristics and sterilizer operator practices from operators familiar with pre-1978 industry conditions. The E/IH 90th percentile of 8 h time-weighted average EO exposures (C90) for highly exposed sterilizer operators was calibrated to match 1978 C90 values from the NSR model. E/IH model C90 exposures were estimated to decrease over time from levels 16 and were four-fold greater than NSR-estimated exposures for workers during 1938–1954 and 1955–1964. This E/IH modeled trend is opposite to that of NSR model predictions of exposures before 1978, suggesting that EPA’s exclusive reliance on the NIOSH cohort to estimate EO cancer risk should be re-examined.

scholarly journals Cancer Risk Assessment and the Biostatistical Revolution of the 1970s—A Reflection

Dose-Response ◽  
2018 ◽  
Vol 16 (4) ◽  
pp. 155932581880640 ◽  
Author(s):  
Kenny Crump
Keyword(s):  
Risk Assessment ◽  
Cancer Risk ◽  
Environmental Protection Agency ◽  
Cancer Risk Assessment ◽  
Toxic Substances ◽  
Multistage Model ◽  
The Public ◽  
Cancer Data ◽  
Assessment Guidelines ◽  
Risk Of Cancer

Before around 1960, assessment of risk from exposure to toxic substances, including risk of cancer, was generally implemented using the NOAEL-safety factor approach that essentially assumed that an exposure threshold existed and exposures below the threshold carried no risk. In the 1970s there came a realization that cancer could develop from a mutation in a single cell and consequently it was unlikely that a threshold existed for substances that could cause such mutations, and that risk could increase linearly with exposure. During this time the Environmental Protection Agency (EPA) was formed and charged with protecting the public from a perceived high risk of environmental cancer. Faced with this difficult task, EPA decided to assess cancer risk by fitting a statistical model to dose-response cancer data and extrapolating to low dose using the fitted model. After some early experimentation EPA selected the Linearized Multistage Model for this fitting, which predicted risk increased linearly with exposure at low exposures. This approach led to an increased emphasis on statistical issues in risk assessment. Today, cancer risk assessment guidelines allow for different approaches depending upon the understanding of a substance's mode of action. However, a review of EPA's experience with current guidelines indicates that most cancer risk assessments still follow procedures similar to those initiated more than 40 years ago.

Quantitative cancer risk assessment for ethylene oxide inhalation in occupational settings

2011 ◽  
Vol 85 (10) ◽  
pp. 1189-1193 ◽  
Author(s):  
Ciriaco Valdez-Flores ◽  
Robert L. Sielken ◽  
M. Jane Teta
Keyword(s):  
Risk Assessment ◽  
Cancer Risk ◽  
Ethylene Oxide ◽  
Cancer Risk Assessment ◽  
Occupational Settings

scholarly journals The EPA Cancer Risk Assessment Default Model Proposal: Moving Away From the LNT

Dose-Response ◽  
2018 ◽  
Vol 16 (3) ◽  
pp. 155932581878984 ◽  
Author(s):  
Edward J. Calabrese ◽  
Jaap C. Hanekamp ◽  
Dima Yazji Shamoun
Keyword(s):  
Public Health ◽  
Risk Assessment ◽  
Cancer Risk ◽  
Environmental Protection Agency ◽  
Model Uncertainty ◽  
Population Based ◽  
Cancer Risk Assessment ◽  
Protection Agency ◽  
Default Model ◽  
Novel Approach

This article strongly supports the Environmental Protection Agency proposal to make significant changes in their cancer risk assessment principles and practices by moving away from the use of the linear nonthreshold (LNT) dose–response as the default model. An alternate approach is proposed based on model uncertainty which integrates the most scientifically supportable features of the threshold, hormesis, and LNT models to identify the doses that optimize population-based responses (ie, maximize health benefits/minimize health harm). This novel approach for cancer risk assessment represents a significant improvement to the current LNT default method from scientific and public health perspectives.

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