Risk of breast cancer among enlisted Army women occupationally exposed to volatile organic compounds

Improving Cancer Care for Women Seeking Services in the Veterans Health Administration Through the Breast and Gynecological Oncology System of Excellence

Women are the fastest growing population among Veterans and have substantial risk factors that increase their likelihood for developing cancer. To ensure that the Department of Veterans Affairs Veterans Health Administration (VHA) offers the best possible cancer care to women Veterans, it established the Breast and Gynecologic Oncology System of Excellence (BGSoE) in 2021. The BGSoE offers telehealth oncology services and a comprehensive cancer navigation program. Veterans are identified through physician referral or through the BGSoE dashboard which integrates ICD-10 codes and text mining from VA electronic health records to identify eligible Veterans with breast or gynecological cancers. Descriptive statistics, including Veteran demographics and geographical location, were derived from BGSoE dashboard data. From January 1, 2021 to March 15, 2024, the BGSoE identified a total of 7,187 incident cases of breast or gynecological cancer among living Veterans. Most cancers were breast (78%) versus gynecological cancers (22%) and 10% of Veterans with breast cancer were identified as male. The average age at diagnosis was 59 for Veterans with breast cancer and 56 for those Veterans with gynecological cancers. Among Veterans in the BGSoE, 28% identified as Black and 6% identified as Hispanic. As the prevalence of women Veterans requiring cancer-related care continues to rise, it will be essential for VHA to evaluate the equitable reach, quality, and acceptability of women-focused cancer health services. The BGSoE focuses on providing high-quality and coordinated clinical cancer care. Veterans Health Administration also established the Center for Oncology Outcomes Review and Gender (COURAGE) to evaluate the BGSoE and continue to strengthen cancer care services in VHA. Initial evaluation objectives include establishing an evidence base regarding Veterans with breast and gynecological cancers, including their experiences with cancer care in the VHA. Eventually, COURAGE will provide ongoing monitoring and evaluation to continue to grow and improve cancer care in the VHA.

Cancer incidence in male and female Canadian Armed Forces personnel and Veterans enrolled between 1976 and 2016: a retrospective population-based cohort study

OBJECTIVES

To describe rates of overall and type-specific primary cancers in Canadian Armed Forces (CAF) personnel and Veterans with a first enrolment in the CAF between 1976 and 2016, with comparisons to the Canadian general population (CGP).

METHODS

This retrospective cohort study linked CAF administrative data to national cancer registries. Primary cancer diagnoses were ascertained from 1976 to 2017. Using age, year and sex-specific rates from the CGP, SIRs and 95% CIs were calculated by sex for all cancers combined and specific cancer types. Subgroup analyses were conducted for service status, rank and international deployment.

RESULTS

Among 210 910 male and 34 940 female CAF personnel and Veterans, 6415 and 1620 incident primary cancer cases were observed, respectively. For cancers overall, CAF personnel and Veterans had lower or similar risk compared with the CGP. Subgroup analyses indicated lower or similar risk compared with the CGP for most cancer types but elevated risk for melanoma in male and female personnel, officers, deployers and male senior non-commissioned members (NCMs); lung and bronchus cancer in male and female junior NCMs; pancreatic cancer in male junior NCMs; testicular cancer in male officers; and cervical cancer in female junior NCMs and non-deployers.

CONCLUSION

CAF personnel and Veterans had lower or equal rates of cancer overall compared with the CGP. Elevated rates were observed for certain cancers within subgroups. Further research to examine time trends and risk factors for cancer outcomes in this population is recommended.

Should Military Veterans Be Classified as High Risk for Prostate Cancer Screening? A Systematic Review and Meta-analysis

OBJECTIVE

To assess the unique risks of prostate cancer among U.S. veterans, and to advocate for improved care by raising awareness of the gaps in current AUA guidelines that do not address the specific needs of military personnel and veterans.

METHODS

Ovid interface, Google Scholar, PubMed, and Medline were searched for studies investigating prostate cancer in veterans published between 1975 and 2023. Search terms: "veteran", "military", "molecular markers", "prostate cancer", "prostate cancer risk", and "military exposure" were used. Articles meeting inclusion criteria underwent analysis, data synthesis, and meta-analysis where applicable.

RESULTS

Results from 45 articles indicate a significant increase in prostate cancer risk associated with exposure to Agent Orange (OR 1.97 [95% CI: 1.64-2.37], P <.00001), aromatic hydrocarbons (OR 1.14 [95% CI: 1.01-1.28], P = .03), and a slight increase with cadmium exposure (OR 1.03 [95% CI: 0.96-1.09], P = .42). While some evidence suggests an association between Camp Lejeune and prostate cancer risk in retrospective cohort studies, logistical regression analysis study did not entirely substantiate this relationship.

CONCLUSION

This review identifies several exposures that elevate prostate cancer risk. Military veterans should be further questioned about their exposures and potentially treated as a high-risk screening group. Further research is warranted to strengthen these associations, as the current evidence remains limited.

Military and occupational exposures among Veterans in the Million Veteran Program by survey self-report: a descriptive study

OBJECTIVE

We aimed to characterise self-reported military and occupational exposures including Agent Orange, chemical/biological warfare agents, solvents, fuels, pesticides, metals and burn pits among Veterans in the Department of Veterans Affairs Million Veteran Program (MVP).

METHODS

MVP is an ongoing longitudinal cohort and mega-biobank of over one million US Veterans. Over 500 000 MVP participants reported military exposures on the baseline survey, and over 300 000 reported occupational exposures on the lifestyle survey. We determined frequencies of selected self-reported occupational exposures by service era, specific deployment operation (1990-1991 Gulf War, Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF)), service in a combat zone and occupational categories. We also explored differences in self-reported exposures by sex and race.

RESULTS

Agent Orange exposure was mainly reported by Vietnam-era Veterans. Gulf War and OEF/OIF Veterans deployed to a combat zone were more likely to report exposures to burn pits, chemical/biological weapons, anthrax vaccination and pyridostigmine bromide pill intake as compared with non-combat deployers and those not deployed. Occupational categories related to combat (infantry, combat engineer and helicopter pilot) often had the highest percentages of self-reported exposures, whereas those in healthcare-related occupations (dentists, physicians and occupational therapists) tended to report exposures much less often. Self-reported exposures also varied by race and sex.

CONCLUSIONS

Our results demonstrate that the distribution of self-reported exposures varied by service era, demographics, deployment, combat experience and military occupation in MVP. Overall, the pattern of findings was consistent with previous population-based studies of US military Veterans.

Carcinogenic industrial air pollution and postmenopausal breast cancer risk in the National Institutes of Health AARP Diet and Health Study

BACKGROUND

Chemicals emitted from industrial facilities include known or suspected mammary carcinogens and endocrine disruptors, but epidemiologic studies are limited. We evaluated associations between air emissions of multiple carcinogenic chemicals and postmenopausal breast cancer risk in a large prospective U.S.

COHORT

METHODS

We used the U.S. Environmental Protection Agency's Toxics Release Inventory to estimate historical airborne emissions (1987-1995) of 19 known and probable carcinogens for participants enrolled (1995-1996) in the NIH-AARP Diet and Health Study. Among 170,402 women, 15,124 breast cancers were diagnosed through 2018. We constructed inverse distance- and wind-weighted average emissions metrics within 1, 2, 5, and 10 km of the enrollment address for each chemical. We estimated multivariable adjusted HRs and 95 % CIs for categories (quartiles, tertiles, medians) of each chemical in association with breast cancer overall and separately by type (invasive, ductal carcinoma in situ) and estrogen receptor (ER) status.

RESULTS

We observed an association between benzene emissions and breast cancer risk that was strongest at 1 km (HRQ4 vs. non-exposed = 2.06, 95 %CI: 1.34-3.17; p-trend = 0.001). The magnitude of the association weakened with increasing distance (2 km HRQ4 vs. non-exposed = 1.17, 95 %CI=0.92-1.49; p-trend = 0.19; 5 km HRQ4 vs. non-exposed = 1.05, 95 %CI=0.94-1.16; p-trend = 0.37; 10 km HRQ4 vs. non-exposed = 0.95, 95 %CI=0.89-1.02; p-trend = 0.19) and appeared to be most relevant for invasive rather than intraductal disease. Overall risk was also elevated for vinyl chloride at 5 km (HR≥median vs. non-exposed = 1.20, 95 %CI=1.01-1.43; p-trend = 0.04), but not 2 km or 10 km. We observed suggestive associations for asbestos, trichloroethylene, and styrene in different subgroup analyses, but risk patterns were not clear across distances. Associations with other chemicals were generally null, with limited evidence of heterogeneity by disease type or ER status.

CONCLUSIONS

An increased risk of breast cancer associated with relatively high levels of industrial benzene emissions warrants additional study, particularly among participants with diverse sociodemographic characteristics that live in areas with higher density of industrial facilities.

Congressional Expansion of Enhancing Breast Cancer Screening and Care at the Veterans Health Administration

Despite high screening rates, breast cancer disparities persist among women veterans because of occupational risks and barriers to access. Three essential bills recently passed in Congress seek to expand access to breast cancer screenings and cancer care within the Veterans Health Administration. The Making Advances in Mammography and Medical Options for Veterans Act expands screening via partnerships with the National Cancer Institute, integrating telescreening and upgrading imaging technology. The Dr. Kate Hendricks Thomas Supporting Expanded Review for Veterans In Combat Environments Act broadens eligibility for those exposed to toxins and personalized risk assessments. The bipartisan Sergeant First Class Health Robinson Honoring our Promise to Address Comprehensive Toxics Act extends benefits for toxin-exposed veterans with presumptive conditions, including breast cancer. Further programs such as National TeleOncology, the Breast & Gynecologic Oncology System of Excellence, and research collaborations between the Veterans Health Administration, National Cancer Institute, and Surveillance, Epidemiology and End Results Program seek to improve access, enhance understanding and care for women veterans with cancer, and mark significant progress in comprehensive care.

Cancer incidence in the US military: An updated analysis

BACKGROUND

Military and general populations differ in factors related to cancer occurrence and diagnosis. This study compared incidence of colorectal, lung, prostate, testicular, breast, and cervical cancers between the US military and general US populations.

METHODS

Data from the US Department of Defense's Automated Central Tumor Registry (ACTUR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program were analyzed. Persons in ACTUR were active-duty members 20-59 years old during 1990-013. The same criteria applied to persons in SEER. Age-adjusted incidence rates, incidence rate ratios, and 95% confidence intervals were calculated by sex, race, age, and cancer stage. Temporal trends were analyzed.

RESULTS

ACTUR had higher rates of prostate and breast cancers, particularly in 40- to 59-year-olds. Further analyses by tumor stage showed this was primarily confined to localized stage. Incidence rates of colorectal, lung, testicular, and cervical cancers were significantly lower in ACTUR than in SEER, primarily for regional and distant tumors in men. Temporal incidence trends were generally similar overall and by stage between the populations, although distant colorectal cancer incidence tended to decrease starting in 2006 in ACTUR whereas it increased during the same period in SEER.

CONCLUSION

Higher rates of breast and prostate cancers in servicemembers 40-59 years of age than in the general population may result from greater cancer screening utilization or cumulative military exposures. Lower incidence of other cancers in servicemembers may be associated with better health status.

Studying full-shift inhalation exposures to volatile organic compounds (VOCs) among Latino workers in very small-sized beauty salons and auto repair shops

Background

One in every 200 US jobs is in a beauty salon or auto repair shop, where workers are regularly exposed to volatile organic compounds (VOCs) that may cause a range of short- and long-term health issues. In these shops, Latino workers are overrepresented and lack culturally and linguistically appropriate industrial hygiene resources. This leaves a gap in knowledge on inhalation exposures to VOCs in this hard-to-reach and ubiquitous worker population.

Objective

Our goal was to recruit hard-to-reach, predominantly Spanish-speaking workers in beauty salons and auto repair shops and monitor total VOC inhalation exposures for over entire work shifts, with minimal impact on workers, clients, and business.

Methods

We developed and refined measurement and exposure assessment methods for personal and area full-shift VOC inhalation exposures.

Results

With minimal participant loss, we measured over 500 h of real-time, personal VOC exposures and recorded activities and other exposure factors for 47 participants, while also documenting chemical inventories and quantifying indoor area concentrations of specific VOCs among 10 auto repair shops and 10 beauty salons.

Conclusion

Lessons learned from our study can assist future studies of inhalation exposures in other hard-to-reach occupational populations.

The association between the incidence of postmenopausal breast cancer and occupational exposure to selected organic solvents, Montreal, Canada, 2008-2011

BACKGROUND

Breast cancer is the most diagnosed cancer among women and recognized risk factors explain 25%-47% of cases. Organic solvents are used widely in the workplace and exposure may increase the risk of developing breast cancer, yet there are insufficient data to confirm this hypothesis. We sought to determine whether past occupational exposures to selected organic solvents were associated with the incidence of invasive breast cancer in postmenopausal women in Montréal, Canada.

METHODS

From a population-based case-control study (2008-2011), using in-depth interviews we elicited information on risk factors and lifetime occupational histories. Industrial hygienists and chemists translated job descriptions into specific chemical and physical exposures. We assessed 11 individual solvents and four solvent groups. Unconditional logistic regression was used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for metrics of past exposures to selected solvents. Exposure metrics included any previous exposure, average frequency in hours per week, duration in years, and average cumulative concentration weighted by hours per workweek exposed.

RESULTS

We enrolled 695 cases and 608 controls. We found increased ORs for average cumulative concentration of exposure to mononuclear aromatic hydrocarbons (OR: 1.52, 95% CI: 1.04, 2.28), chlorinated alkanes (OR: 2.42, 95% CI: 1.23, 5.68), toluene (OR: 1.59, 95% CI: 1.02, 2.59), and a group of organic solvents with reactive metabolites (OR: 1.53, 95% CI: 1.08, 2.24). Positive associations were found across all exposure metrics and were higher among women with estrogen-positive/progesterone-negative tumors.

CONCLUSION

Our findings suggest occupational exposure to certain organic solvents may increase the risk of incident postmenopausal breast cancer.

Long-term in situ air quality assessment in closed environments: A gas chromatography-ion mobility spectrometry applicability study

Contemporary life is mostly spent in indoor spaces like private houses, workplaces, vehicles and public facilities. Nonetheless, the air quality in these closed environments is often poor which leads to people being exposed to a vast range of toxic and hazardous compounds. Volatile organic compounds (VOCs) are among the main factors responsible for the lack of air quality in closed spaces and, in addition, some of them are particularly hazardous to the human organism. Considering this fact, we conducted daily in situ air analyses over 1 year using a gas chromatography-ion mobility spectrometry (GC-IMS) device in an indoor location. The obtained results show that 10 VOCs were consistently present in the indoor air throughout the entire year, making them particularly important for controlling air quality. All of these compounds were successfully identified, namely acetic acid, acetone, benzene, butanol, ethanol, isobutanol, propanoic acid, propanol, 2-propanol and tert-butyl methyl ether. The behaviour of the total VOCs (tVOCs) intensity during the period of analysis and the relative variation between consecutive months were studied. It was observed that the overall trend of tVOCs closely mirrored the variation of air temperature throughout the year suggesting their strong correlation. The results obtained from this study demonstrate the high quality and relevance of the data, highlighting the suitability of GC-IMS for in situ long-term air quality assessment in indoor environments and, consequently, for identifying potential health risks for the human organism in both short-term and long-term exposure scenarios.

Post-9/11 deployment history and the incidence of breast cancer among women veterans

PURPOSE

To determine if women Veterans who deployed in support of Operations Enduring Freedom/Iraqi Freedom (OEF/OIF) would show a greater likelihood of breast cancer (BC) than other women Veterans.

METHODS

This was a retrospective cohort study of women aged <60 years who received Veterans Affairs medical center primary care, 2001-2021. The exposure was OEF/OIF deployment and the outcome was a BC diagnosis after entering Veterans Affairs care. Poisson models evaluated the association between deployment and BC incidence, covarying demographics, lifestyle factors, and hormonal contraceptive and hormone replacement therapy use. Analyses were also stratified by age and race, and a sensitivity analysis adjusted for healthcare utilization over the initial 2 years.

RESULTS

Of 576,601 women, 24.6% (n = 141,935) deployed during post-9/11 conflicts. Across follow-up [median: 8.2 years], 1.2% women were diagnosed with BC. Those who deployed in support of OEF/OIF were 23% less likely to be diagnosed with BC than women who did not deploy (95% CI: 0.73, 0.86). The association remained in stratified models and when including healthcare utilization.

CONCLUSIONS

Despite the exposures of OEF/OIF deployment, there was a significantly lower incidence of BC among women who deployed versus not, possibly due to a healthy soldier effect or to differences in screening.

Employment and risk of female breast cancer in Denmark

BACKGROUND

Occupational exposures may play a role in breast cancer etiology, and research focusing on identifying high-risk workplaces is important to advance the understanding and prevention of breast cancer.

METHODS

We undertook a population-based nested case-control study among women who were less than 70 years of age and born in Denmark, based on registry data including 38,375 breast cancer cases and 191,875 controls matched on year of birth, with information on lifetime work history. Odds ratios for women ever employed in a job branch were adjusted for socioeconomic status and reproductive variables.

RESULTS

Adjusted odds ratios of less than 0.75 were observed for several occupations in agriculture, hunting, forestry, and fishing, while increased risk patterns (odds ratios greater than 1.50) were noted for a number of production occupations, including employment in graphics and printing, and metal and machinery production. In services, several military professions were also associated with a high increased breast cancer risk.

CONCLUSIONS

The study shows a variation in the risk of female breast cancer by employment in different industrial and occupational sectors, and suggests that certain occupational exposures, for example, outdoor work, organic solvents, polycyclic aromatic hydrocarbons (PAHs), and night-shift work may play a role in the risk of breast cancer. Further hypothesis-testing studies focusing on these employments with a detailed assessment of specific occupational exposures are warranted.

Occupational exposure to organic solvents and breast cancer risk: a systematic review and meta-analysis

Breast cancer is the most common cancer worldwide. Recent studies suggest that organic solvent exposure could be closely related to breast cancer, although the evidence remains controversial. Thus, we evaluated existing epidemiological evidence for the association between occupational solvent exposure and breast cancer. PubMed, Embase, and Cochrane Library were searched to identify published case-control and cohort studies that addressed occupational exposure to organic solvents and breast cancer, up to April, 2021. Meta-analyses using random-effects models were conducted to obtain the pooled odds ratios (OR) and 95% confidence intervals (CI) on the incidence of breast cancer in relation to occupational exposure. The pooled OR of breast cancer among workers exposed to organic solvents overall was 1.18 (95%CI, 1.11 ~ 1.25; I² = 76.3%; 24 studies), compared to those with no exposure. After stratification by menopause and study location, it was revealed that the association between occupational exposure to organic solvents and the risk of breast cancer in postmenopausal women (OR, 1.35; 95% CI, 1.09 ~ 1.67; I² = 73.4%; 7 studies) was significant, and there was also a clear association in workers in Europe (OR, 1.21; 95% CI, 1.12 ~ 1.32; I² = 82.9%; 13 studies). We observed a significant association between occupational exposure to organic solvents and breast cancer in both cohort and case-control studies.

Brain cancer incidence: a comparison of active-duty military and general populations

BACKGROUND

In the USA, brain cancer disproportionately affects young adults. The US military has a younger age structure than the general population and may have differential exposures related to brain cancer. This study aimed to compare the incidence rates of brain cancer in the active-duty military and general populations to provide clues for future etiologic research. The rates between military service branches were also compared.

METHODS

The data for this study were from the Department of Defense's Automated Central Tumor Registry (ACTUR) and the National Cancer Institute's Surveillance, Epidemiology, and End Results 9 (SEER-9) registries. Age- and sex-adjusted incidence rates of malignant neuroepithelial brain cancer among adults 20-54 years of age from 1990-2013 were calculated and compared between the two populations, given as incidence rate ratios (IRRs) with 95% confidence intervals (CIs).

RESULTS

The age and sex-adjusted incidence rate for malignant neuroepithelial brain cancer was significantly lower in the active-duty population than in the US general population (IRR = 0.62, 95% CI,  0.56-0.68). The reduced incidence rate in the active-duty population was observed in men, all races, individuals 20-44 of age, and for all histological subtypes and time periods assessed. There were no significant differences in rates between the military service branches.

CONCLUSION

The incidence rates of neuroepithelial brain cancer were lower in the active-duty military population than the US general population. This study highlights the need for more research to enhance our understanding of variations in brain cancer incidence between these two populations.

Screening High-Risk Women Veterans for Breast Cancer

BACKGROUND

Within the US Department of Veterans Affairs (VA), breast cancer prevalence has more than tripled from 1995 to 2012. Women veterans may be at an increased breast cancer risk based on service-related exposures and posttraumatic stress disorder (PTSD).

METHODS

Women veterans aged ≥ 35 years with no personal history of breast cancer were enrolled at 2 urban VA medical centers. We surveyed women veterans for 5-year and lifetime risks of invasive breast cancer using the Gail Breast Cancer Risk Assessment Tool (BCRAT). Data regarding demographics, PTSD status, eligibility for chemoprevention, and genetic counseling were also collected. Descriptive statistics were used to determine results.

RESULTS

A total of 99 women veterans participated, of which 60% were Black. In total, 35% were high risk with a 5-year BCRAT > 1.66%. Breast biopsies had been performed in 22% of our entire population; 57% had a family history positive for breast cancer. Comparatively, in our high-risk Black population, 33% had breast biopsies and 94% had a family history. High-risk patients were referred for chemoprevention; 5 accepted and 13 were referred for genetic counseling. PTSD was present in 31% of the high-risk subgroup.

CONCLUSIONS

A high percentage of Black patients participated in this pilot study, which also showed an above average rate of PTSD among women veterans who are at high risk for developing breast cancer. Historically, breast cancer rates among Black women are lower than those found in the general population. High participation among Black women veterans in this pilot study uncovered the potential for further study of this population, which is otherwise underrepresented in research. Limitations included a small sample size, exclusively urban population, and self-selection for screening. Future directions include the evaluation of genetic and molecular mutations in high risk Black women veterans, possibly even a role for PTSD epigenetic changes.

The Impact of Mammography Screening Guideline Changes Among Women Serving in the U.S. Military

INTRODUCTION

The U.S. Preventive Services Task Force (USPSTF) modified their screening guidelines for breast cancer in November 2009. Previous studies evaluated the impact of these guideline changes among privately and Medicare insured populations. Women in the military form a unique population exposed to many social, environmental, and occupational hazards that may increase breast cancer incidence. By evaluating mammography screening rates among women in the military before and after the USPSTF guideline changes, this study evaluated the impact of the USPSTF breast cancer guideline change on screening mammography use within the military population and determined whether current guidelines were followed for this high-risk population with universal health care access.

MATERIALS AND METHODS

This study evaluated the impact of the 2009 guideline changes among the population of universally insured military servicewomen, comparing the proportion of active duty women aged 40 to 64 receiving mammograms from fiscal years 2006 to 2015 using an interrupted time series analysis. Stratified analyses evaluated differences by age (aged 40-49, 50-64), race, military branch, and rank. This research is considered exempt by the Uniformed Services University Institutional Review Board.

RESULTS

The proportion of insured military servicewomen receiving mammograms increased from October 2005 through September 2009. A significant decrease occurred in the first quarter of 2010 following the publication of the screening guideline update. From this new baseline, the proportion of women screened increased again through September 2015. Comparative analyses showed more pronounced effects both immediately and over time among the women aged 50 to 64 compared to those aged 40 to 49 years and among older enlisted women compared with their officer counterparts. The patterns were near identical in all subgroups; however, no changes in rate were evident among Air Force and black servicewomen aged 50 to 64 and Army and Navy/Marine Corps servicewomen aged 40 to 49 years. No racial disparities in screening or impact were noted.

CONCLUSIONS

The USPSTF guidelines had differential impacts among some subpopulations. While older women, aged 50 to 64 years, had a greater temporary reduction immediately after the guideline change, younger women aged 40 to 49 years had a longer-term reduction in screening following the guideline changes. No racial disparities in the proportion screened or in the impact of the guideline change were noted in this population with universal health coverage. The lack of Department of Defense standard breast cancer screening guidelines was evident from the different patterns of mammography utilization observed among military branches. To completely understand the impact of the updated screening guidelines, future studies must incorporate research focusing on changes in breast cancer morbidity and mortality as well as updated cost-benefit analyses.

Pollution Characteristics and Health Risk Assessment of Summertime Atmospheric Volatile Halogenated Hydrocarbons in a Typical Urban Area of Beijing, China

Twenty-three atmospheric volatile halogenated hydrocarbons (VHHs) were detected in a typical urban area of Beijing, China from 24 August to 4 September, 2012. The mean and range in daily mass concentrations of the 23 VHHs were 30.53 and 13.45–76.33 µg/m3, respectively. Seven of those VHHs were controlled ozone-depleting substances in China, with a mean of 12.95 µg/m3, accounting for 42.43% of the total. Compared with other national and international cities, the concentrations of the selected 11 VHHs in this study were relatively higher. Dichloroethane had the highest mass concentration, followed by difluorochloromethane. Maxima of total VHHs occurred within the period 8:30–9:00 a.m., while minima occurred during 1:30–2:00 p.m. Source apportionment suggested that the main sources of VHHs in the study area were solvents usage and industrial processes, leakage of chlorofluorocarbons banks, refrigerants, and fumigant usage. Among the selected 7 VHHs, trichloromethane, tetrachloromethane, 1,2-dichloroethane, and 1,4-dichlorobenzene posed potential carcinogenic risks to exposed populations, while none of the selected 11 VHHs posed appreciable non-carcinogenic risks to exposed populations. The carcinogenic risks from atmospheric VHHs in Beijing are higher than in other Chinese cities, indicating that it is necessary to implement immediate control measures for atmospheric VHHs in Beijing.

Incidence Rates of Gynecologic Cancers in the U.S. Active Duty Military Population

INTRODUCTION

Despite an increasing number of female service members, incidence rates of gynecologic cancers (other than cervical cancer) have not been previously documented in the U.S. active duty military population. This study sought to determine the incidence rates of all gynecologic, including peritoneal, malignancies in the U.S. Active Duty population compared to the general US population as reported in the Surveillance, Epidemiology, and End Results Program database.

MATERIALS AND METHODS

Gynecologic cancers diagnosed in U.S. Active Duty women aged 20-59 between 2004 and 2013 were retrospectively ascertained. Cancer cases were identified in both the Automated Central Tumor Registry and the Military Health System Data Repository. All cases in Automated Central Tumor Registry plus cases recorded in Military Health System Data Repository, but not duplicative of Automated Central Tumor Registry cases, were included. Age-specific and age-adjusted incidence rates were calculated in military and Surveillance, Epidemiology, and End Results cases.

RESULTS

In U.S. Active Duty women, 327 incident cases of gynecologic cancer were identified. There were 110 cases of cervical cancer, 40 cases of endometrial cancer, 152 cases of ovarian cancer, and 25 other gynecologic malignancies. Of the 327 cases, 154 were ascertained from the Automated Central Tumor Registry database and the remainder from Military Health System Data Repository claims data. The age-adjusted rate of all gynecologic cancers for U.S. Active Duty women was 49.17 per 105 (95%CI 37.58, 65.12), while the age-adjusted rate for Surveillance, Epidemiology, and End Results -18 was 42.09 per 105 (95%CI 41.83, 42.35). The kappa coefficient assessing the overlap between the data sources was -0.1937. Though insufficient in numbers for statistical analysis, the observed proportion of ovarian to cervical cancer cases in active duty women < 45 years of age was substantially greater than in the general population.

CONCLUSIONS

U.S. Active Duty women exhibited a similar age-adjusted rate of gynecologic cancer as the general US population. There was suboptimal overlap between the Automated Central Tumor Registry and Military Health System Data Repository databases, indicating the necessity of using both databases in order to obtain reliable data in the active duty population. This study is the current best estimate of a baseline rate of gynecologic cancer in U.S. active duty military women. This rate might change over time as women's roles and exposures in recent and future military conflicts evolve.

Volatile organic compounds in 169 energy-efficient dwellings in Switzerland

Exposure to elevated levels of certain volatile organic compounds (VOCs) in households has been linked to deleterious health effects. This study presents the first large-scale investigation of VOC levels in 169 energy-efficient dwellings in Switzerland. Through a combination of physical measurements and questionnaire surveys, we investigated the influence of diverse building characteristics on indoor VOCs. Among 74 detected compounds, carbonyls, alkanes, and alkenes were the most abundant. Median concentration levels of formaldehyde (14 μg/m³ ), TVOC (212 μg/m³ ), benzene (<0.1 μg/m³ ), and toluene (22 μg/m³ ) were below the upper exposure limits. Nonetheless, 90% and 50% of dwellings exceeded the chronic exposure limits for formaldehyde (9 μg/m³ ) and TVOC (200 μg/m³ ), respectively. There was a strong positive correlation among VOCs that likely originated from common sources. Dwellings built between 1950s and 1990s, and especially, those with attached garages had higher TVOC concentrations. Interior thermal retrofit of dwellings and absence of mechanical ventilation system were associated with elevated levels of formaldehyde, aromatics, and alkanes. Overall, energy-renovated homes had higher levels of certain VOCs compared with newly built homes. The results suggest that energy efficiency measures in dwellings should be accompanied by actions to mitigate VOC exposures as to avoid adverse health outcomes.

Full employment history of Danish firefighters potentially involving additional exposures, 1964-2015

BACKGROUND

This study aimed to demonstrate the possibility of using data on full employment history to describe occupational patterns of Danish firefighters that may indicate additional hazards encountered by these workers.

METHODS

An established cohort of Danish full-time and part-time/volunteer firefighters was used in the study (N = 9952) as well as occupational history covering the period 1964-2015, which was retrieved from a nationwide pension fund with compulsory membership. The most frequently held employments other than firefighting, together with temporal patterns of these employments, were explored in descriptive analyses.

RESULTS

Besides working in the firefighter service, both full-time and part-time/volunteer firefighters had frequently been employed in the military and the police (55% and 38%) and more than 10% of both types of firefighters in a number of blue-collar jobs, including construction-related jobs (eg, masonry, joining, carpentry, insulation, and installation), laundry and dry cleaning, the auto industry, and rubber and plastic production. Part-time/volunteer firefighters had more frequently been employed in the machine industry, fabricated metal production, the wood and furniture industry, and farming. Both types of firefighters were initially employed in other jobs before their employment in firefighting.

CONCLUSION

The cohort of Danish firefighters had frequently been working in other professions potentially exposing them to additional hazardous exposures, and occupational patterns varied by type of firefighter employment. Accounting for full employment history is, for that reason, considered essential when exploring associations between specific professions and health outcomes.

Work and Female Breast Cancer: The State of the Evidence, 2002-2017

The authors undertook a scoping review to assess the literature from 2002 to 2017 on the relationship between occupation and female breast cancer. Case-control, cohort, and meta-analytic studies suggest that women working as flight attendants, in medical professions, some production positions, sales and retail, and scientific technical staff are likely to have elevated risk of breast cancer. In addition, occupational exposures to night-shift work, ionizing radiation, some chemicals, job stress, and sedentary work may increase risk of breast cancer. Occupational physical activity appears to decrease risk. Workplace exposures to passive smoke and occupational exposure to nonionizing radiation do not appear to affect breast cancer risk. Some studies of occupational categories and workplace exposures indicate that risk may be modified by duration of exposure, timing of exposure, dose, hormone-receptor subtypes, and menopausal status at diagnosis. The compelling data from this review reveal a substantial need for further research on occupation and breast cancer.

Evaluation of contaminated drinking water and male breast cancer at Marine Corps Base Camp Lejeune, North Carolina: a case control study

BACKGROUND

Solvents contaminated drinking water supplies at Marine Corps Base Camp Lejeune during 1950s-1985.

METHODS

We conducted a case-control study among Marines to evaluate associations between residential exposure to contaminated drinking water at Camp Lejeune and male breast cancer risk. The study included 71 male breast cancer cases and 373 controls identified from the Department of Veteran's Affairs (VA) cancer registry whose military personnel records were available. Controls were selected from cancers not known to be associated with solvent exposure and included 270 skin cancers, 71 mesotheliomas, and 32 bone cancers. Base assignment and risk factor information came from military personnel and VA records. Groundwater contaminant fate/transport and distribution system models provided monthly estimated residential contaminant levels. We conducted exact logistic regression using the 50th percentile level among exposed controls to create low and high exposure categories. We calculated 95% confidence intervals (CIs) to indicate precision of effect estimates. Exploratory analyses used proportional hazards methods to evaluate associations between exposures and age at diagnosis.

RESULTS

After adjusting for age at diagnosis, race, and service in Vietnam, the odds ratio (OR) for ever stationed at Camp Lejeune was 1.14 (95% CI: 0.65, 1.97). Adjusted ORs for high residential cumulative exposures to tetrachloroethylene (PCE), t-1,2 dichloroethylene (DCE), and vinyl chloride were 1.20 [95% CI: 0.16-5.89], 1.50 [95% CI: 0.30-6.11], 1.19 [95% CI: 0.16-5.89], respectively, with a monotonic exposure response relationship for PCE only. However these results were based on two or three cases in the high cumulative exposure categories. Ever stationed at Camp Lejeune and high cumulative exposures to trichloroethylene (TCE), PCE, DCE and vinyl chloride were associated with earlier age at onset for male breast cancer; hazard ratios ranged from 1.4-2.7 with wide confidence intervals for cumulative exposure variables.

CONCLUSION

Findings suggested possible associations between male breast cancer and being stationed at Camp Lejeune and cumulative exposure to PCE, DCE, and vinyl chloride. TCE, PCE, DCE and vinyl chloride cumulative exposures showed possible associations with earlier age at onset of male breast cancer. However, this study was limited by small numbers of cases in high exposure categories.

Occupational exposure to solvents and risk of breast cancer

BACKGROUND

Occupational exposure to some organic solvents may increase risk of breast cancer.

METHODS

In a population-based case-control study, 1,205 women diagnosed with primary breast cancer between 2009 and 2011 were drawn from the Western Australian Cancer Registry and matched to 1,789 controls from the electoral roll. Exposure to solvents was determined through telephone interviews using OccIDEAS.

RESULTS

About a third of women were occupationally exposed to solvents. Age adjusted breast cancer risks were elevated for women who had been exposed to aliphatic solvents odds ratio (OR) 1.21 (95%CI 0.99-1.48) and aromatic solvents OR 1.21 (95%CI 0.97-1.52). For most solvents the ORs were higher for those diagnosed before menopause.

CONCLUSIONS

This study suggests that there may be an association between occupational exposure to aliphatic and aromatic solvents and the risk of breast cancer at the low levels of exposure experienced by women in this study.

Hazardous air pollutants and breast cancer risk in California teachers: a cohort study

BACKGROUND

Studies suggest that higher breast cancer rates in urban areas persist after accounting for the prevalence of known risk factors, leading to speculation that urban environmental exposures, such as air pollution, may play a role in the etiology of breast cancer. Combining modeled ambient air concentrations with data from a large prospective cohort of California women with over 15 years of follow-up, we examined the relationship between breast cancer incidence and modeled concentrations of air pollutants shown to be mammary gland carcinogens (MGCs).

METHODS

The study population of 112,378 California Teachers Study participants included 5,676 women diagnosed with invasive breast cancer. Modeled annual average ambient air concentrations of 24 MGCs from the U.S. Environmental Protection Agency were linked to participants' addresses. Cox proportional hazards models were used to estimate hazard rate ratios and 95% confidence intervals associated with residential MGC levels. MGCs were examined individually and as a combined summary variable for all participants, in selected subsets, and by tumor hormone responsiveness.

RESULTS

Initial models yielded some evidence for increased risk for several compounds, including acrylamide, carbon tetrachloride, chloroprene, 4,4'-methylene bis(2-chloroaniline), propylene oxide, and vinyl chloride, but after adjustment for multiple comparisons, only results for propylene oxide and vinyl chloride remained statistically significant. In subset analyses, estrogen-receptor positive or progesterone-receptor positive (ER+/PR+) tumors were associated with higher ambient levels of acrylamide, benzidine, carbon tetrachloride, ethylidene dichloride, and vinyl chloride, while ER-/PR- tumors were associated with higher ambient levels of benzene. Interesting results for different compounds were observed within certain subsets of the population.

CONCLUSION

While our initial models yielded several elevated risk estimates, after adjusting for multiple comparisons and breast cancer risk factors, most hazard ratios were no longer statistically significant. Our subset analyses, however, suggest that elevated risk may be associated with some compounds for certain subgroups of interest. A summary variable for all 24 MGCs did not offer any advantage over the models for individual compounds. Results must be interpreted cautiously, as estimated exposure was limited to modeled annual average ambient air concentrations, and could not account for other sources or routes other than inhalation.

Breast cancer risk after occupational solvent exposure: the influence of timing and setting

Organic solvents are ubiquitous in occupational settings where they may contribute to risks for carcinogenesis. However, there is limited information on organic solvents as human breast carcinogens. We examined the relationship between occupational exposure to solvents and breast cancer in a prospective study of 47,661 women with an occupational history in the Sister Study cohort. Occupational solvent exposure was categorized using self-reported job-specific solvent use collected at baseline. Multivariable Cox regression analyses were used to assess breast cancer risk, adjusting for established breast cancer risk factors. A total of 1,798 women were diagnosed with breast cancer during follow-up, including 1,255 invasive cases. Overall the risk of invasive breast cancer was not associated with lifetime exposure to solvents [HR, 1.04; 95% confidence interval (CI), 0.88-1.24]. Parous women who worked with solvents before their first full-term birth had an increased risk of estrogen receptor-positive invasive breast cancer compared with women who never worked with solvents (HR, 1.39; 95% CI, 1.03-1.86). A significantly elevated risk for estrogen receptor-positive invasive breast cancer was associated with solvent exposure among clinical laboratory technologists and technicians (HR, 2.00; 95% CI, 1.07-3.73). Occupational exposure to solvents before first birth, a critical period of breast tissue differentiation, may result in increased vulnerability for breast cancer. Our findings suggest a need for future studies in this area to focus on exposure time windows and solvent types in different occupational settings.

The mammary gland carcinogens: the role of metal compounds and organic solvents

The increased rate of breast cancer incidences especially among postmenopausal women has been reported in recent decades. Despite the fact that women who inherited mutations in the BRCA1 and BRCA2 genes have a high risk of developing breast cancer, studies have also shown that significant exposure to certain metal compounds and organic solvents also increases the risks of mammary gland carcinogenesis. While physiological properties govern the uptake, intracellular distribution, and binding of metal compounds, their interaction with proteins seems to be the most relevant process for metal carcinogenicity than biding to DNA. The four most predominant mechanisms for metal carcinogenicity include (1) interference with cellular redox regulation and induction of oxidative stress, (2) inhibition of major DNA repair, (3) deregulation of cell proliferation, and (4) epigenetic inactivation of genes by DNA hypermethylation. On the other hand, most organic solvents are highly lipophilic and are biotransformed mainly in the liver and the kidney through a series of oxidative and reductive reactions, some of which result in bioactivation. The breast physiology, notably the parenchyma, is embedded in a fat depot capable of storing lipophilic xenobiotics. This paper reviews the role of metal compounds and organic solvents in breast cancer development.

Endocrine-disrupting chemicals: associated disorders and mechanisms of action

The incidence and/or prevalence of health problems associated with endocrine-disruption have increased. Many chemicals have endocrine-disrupting properties, including bisphenol A, some organochlorines, polybrominated flame retardants, perfluorinated substances, alkylphenols, phthalates, pesticides, polycyclic aromatic hydrocarbons, alkylphenols, solvents, and some household products including some cleaning products, air fresheners, hair dyes, cosmetics, and sunscreens. Even some metals were shown to have endocrine-disrupting properties. Many observations suggesting that endocrine disruptors do contribute to cancer, diabetes, obesity, the metabolic syndrome, and infertility are listed in this paper. An overview is presented of mechanisms contributing to endocrine disruption. Endocrine disruptors can act through classical nuclear receptors, but also through estrogen-related receptors, membrane-bound estrogen-receptors, and interaction with targets in the cytosol resulting in activation of the Src/Ras/Erk pathway or modulation of nitric oxide. In addition, changes in metabolism of endogenous hormones, cross-talk between genomic and nongenomic pathways, cross talk with estrogen receptors after binding on other receptors, interference with feedback regulation and neuroendocrine cells, changes in DNA methylation or histone modifications, and genomic instability by interference with the spindle figure can play a role. Also it was found that effects of receptor activation can differ in function of the ligand.

Oral contraceptive use among women in the military and the general U.S. population

OBJECTIVE

To compare oral contraceptive (OC) use during a 12-month period among women aged 18-39 years in the U.S. military and the general U.S. population using data from the Military Health System Management Analysis and Reporting Tool (M2) and the National Health and Nutrition Examination Survey (NHANES), respectively.

METHODS

OC use was age adjusted to the 2000 U.S. Census population. Comparisons between the military (n = 83,181) and the general population (unweighted n = 360), as well as between the military branches, were conducted overall and stratified by age, race/ethnicity, and marital status.

RESULTS

OC use was higher in the military (34%) than in the general population (29%, p < 0.05). This difference increased with age and was most pronounced among Hispanics (military, 32.2%; general population, 19.8%). Within the military, OC use was highest in the Air Force (39%) and lowest in the Army (30%, p < 0.05).

CONCLUSIONS

These findings suggest that OC use differs between the military and the general population and within the military by service branch. Further studies that assess whether OC use is related to variations in health outcomes between these two populations and within the military are warranted.

Diffusion-controlled reference material for VOC emissions testing: proof of concept

Because of concerns about indoor air quality, there is growing awareness of the need to reduce the rate at which indoor materials and products emit volatile organic compounds (VOCs). To meet consumer demand for low emitting products, manufacturers are increasingly submitting materials to independent laboratories for emissions testing. However, the same product tested by different laboratories can result in very different emissions profiles because of a general lack of test validation procedures. There is a need for a reference material that can be used as a known emissions source and that will have the same emission rate when tested by different laboratories under the same conditions. A reference material was created by loading toluene into a polymethyl pentene film. A fundamental emissions model was used to predict the toluene emissions profile. Measured VOC emissions profiles using small-chamber emissions tests compared reasonably well to the emissions profile predicted using the emissions model, demonstrating the feasibility of the proposed approach to create a diffusion-controlled reference material.

PRACTICAL IMPLICATIONS

To calibrate emissions test chambers and improve the reproducibility of VOC emission measurements among different laboratories, a reference material has been created using a polymer film loaded with a representative VOC. Initial results show that the film's VOC emission profile measured in a conventional test chamber compares well to predictions based on independently determined material/chemical properties and a fundamental emissions model. The use of such reference materials has the potential to build consensus and confidence in emissions testing as well as 'level the playing field' for product testing laboratories and manufacturers.

Occupational exposure to organic solvents and breast cancer in women

BACKGROUND

Although studies in rodents suggest possible associations between exposure to organic solvents and breast cancer, the evidence in humans is limited.

METHODS

We evaluated job histories of 2383 incident breast cancer cases diagnosed during 2000-2003, and 2502 controls who participated in a large population-based case-control study in Poland. Industrial hygienists reviewed occupational histories and developed exposure metrics for total organic solvents and benzene. Unconditional logistic regression analyses estimated ORs and 95% CIs as the measure of association with breast cancer, controlling for breast cancer risk factors. Stratified analyses examined the potential modification by known breast cancer risk factors. Associations were also evaluated by oestrogen and progesterone receptor status and by other clinical characteristics of the tumours using polytomous regression analyses.

RESULTS

Women who ever worked at jobs with organic solvents exposure had a small, non-significant increase in breast cancer risk (OR=1.16; 95% CI 0.99 to 1.4). A significant association was present for oestrogen receptor- and progesterone receptor-negative tumours (OR 1.40; 95% CI 1.1 to 1.8), but there was no association with tumours with both positive receptors (OR 0.97; 95% CI 0.8 to 1.2 (p heterogeneity: 0.008)). We did not observe trends with increasing level of exposure. Known breast cancer risk factors did not modify the association between organic solvents and breast cancer risk. No association with breast cancer was found for benzene exposure (OR 1.00; 95% CI 0.8 to 1.3).

CONCLUSION

Our study provides weak evidence for a possible association between occupational exposure to organic solvents as a class and breast cancer risk. The association might be limited to hormone receptor-negative tumours.

Cancer incidence in the U.S. military population: comparison with rates from the SEER program

The U.S. active-duty military population may differ from the U.S. general population in its exposure to cancer risk factors and access to medical care. Yet, it is not known if cancer incidence rates differ between these two populations. We therefore compared the incidence of four cancers common in U.S. adults (lung, colorectal, prostate, and breast cancers) and two cancers more common in U.S. young adults (testicular and cervical cancers) in the military and general populations. Data from the Automated Central Tumor Registry (ACTUR) of the Department of Defense and the nine cancer registries of the Surveillance, Epidemiology and End Results (SEER) of the National Cancer Institute for the years 1990 to 2004 for persons with ages 20 to 59 years were analyzed. Incidence rates were significantly lower in the military population for colorectal cancer in White men, lung cancer in White and Black men and White women, and cervical cancer in Black women. In contrast, incidence rates of breast and prostate cancers were significantly higher in the military among Whites and Blacks. Incidence rates of testicular cancer did not differ between ACTUR and SEER. Although the numbers of diagnoses among military personnel were relatively small for temporal trend analysis, we found a more prominent increase in prostate cancer in ACTUR than in SEER. Overall, these results suggest that cancer patterns may differ between military and nonmilitary populations. Further studies are needed to confirm these findings and explore contributing factors.

Environmental pollutants and breast cancer: epidemiologic studies

Laboratory research has shown that numerous environmental pollutants cause mammary gland tumors in animals; are hormonally active, specifically mimicking estrogen, which is a breast cancer risk factor; or affect susceptibility of the mammary gland to carcinogenesis. An assessment of epidemiologic research on these pollutants identified in toxicologic studies can guide future research and exposure reduction aimed at prevention. The PubMed database was searched for relevant literature and systematic critical reviews were entered in a database available at URL: www.silentspring.org/sciencereview and URL: www.komen.org/environment (accessed April 10, 2007). Based on a relatively small number of studies, the evidence to date generally supports an association between breast cancer and polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in conjunction with certain genetic polymorphisms involved in carcinogen activation and steroid hormone metabolism. Evidence regarding dioxins and organic solvents is sparse and methodologically limited but suggestive of an association. Methodologic problems include inadequate exposure assessment, a lack of access to highly exposed and unexposed populations, and a lack of preclinical markers to identify associations that may be obscured by disease latency. Among chemicals identified in toxicologic research as relevant to breast cancer, many have not been investigated in humans. The development of better exposure assessment methods is needed to fill this gap. In the interim, weaknesses in the epidemiologic literature argue for greater reliance on toxicologic studies to develop national policies to reduce chemical exposures that may be associated with breast cancer. Substantial research progress in the last 5 years suggests that the investigation of environmental pollutants will lead to strategies to reduce breast cancer risk.

Occupational Exposures and Breast Cancer Among Women Textile Workers in Shanghai

BACKGROUND

Breast cancer incidence rates have been increasing in China over the past 2 decades. Most studies have focused on reproductive, dietary, and genetic risk factors. Little is known about the contribution of occupational exposures.

METHODS

We conducted a case-cohort study within a cohort of female textile workers who had participated in a randomized trial of breast self-examination in Shanghai, China. We compared 1709 incident breast cancer cases with an age-stratified reference subcohort (n = 3155 noncases). Cox proportional hazards modeling, adapted for the case-cohort design, was used to estimate hazard ratios for breast cancer in relation to duration of employment in various job processes and duration of exposure to several agents. We also evaluated the associations of cotton dust and endotoxin with breast cancer.

RESULTS

Cumulative exposures to cotton dust and endotoxin demonstrated strong inverse gradients with breast cancer risk when exposures were lagged by 20 years (trend P-values <0.001). We did not observe consistent associations with exposures to electromagnetic fields, solvents, or other chemicals.

CONCLUSION

Endotoxin or other components of cotton dust exposures may have reduced risks for breast cancer in this cohort, perhaps acting at early stages of carcinogenesis. Replication of these findings in other occupational settings with similar exposures will be needed to confirm or refute any hypothesis regarding protection against breast cancer.