Estimation of the health risks associated with polychlorinated biphenyl (PCB) concentrations found onboard older U.S. Navy vessels

Source apportionment of polychlorinated biphenyls in the sediment of the Newtown Creek superfund site

Polychlorinated biphenyls (PCBs) are a primary contaminant of potential concern at the Newtown Creek superfund site. Measurements of PCBs in hundreds of samples of sediment (surface and cores) within Newtown Creek and at nearby reference locations were obtained from the Remedial Investigation (RI) databases. This data set was analyzed using Positive Matrix Factorization (PMF). A weight-of-evidence approach was used to attribute the PMF-generated fingerprints to sources. The PMF analysis generated eight factors (fingerprints or sources) that represent primary sources, such as Aroclors, as well as secondary sources, including the East River and Combined Sewer Outfalls (CSOs). In addition to the high-production volume Aroclors (1016/1242, 1248, 1254, and 1260), some less-widely used Aroclors (1232 and 1268) were found in Newtown Creek sediment. Aroclor 1268 is disproportionately abundant in the deepest sediments, while PCBs likely from CSOs are relatively more abundant in surface sediment.

A nested case-control study of serum polychlorinated biphenyls and papillary thyroid cancer risk among U.S. military service members

BACKGROUND AND OBJECTIVES

Although polychlorinated biphenyls (PCBs) were banned decades ago, populations are continuously exposed to PCBs due to their persistence and bioaccumulation/biomagnification in the environment. Results from limited epidemiologic studies linking PCBs to thyroid cancer have been inconclusive. This study aimed to investigate the association between individual PCBs and PCB mixture and papillary thyroid cancer (PTC), the most common thyroid cancer histologic subtype.

METHODS

We carried out a nested case-control study including 742 histologically confirmed PTC cases diagnosed in 2000-2013 and 742 individually matched controls among U.S. military service members. Pre-diagnostic serum samples that were collected on average nine years before PTC diagnosis were used to measure PCB congeners by gas chromatography isotope dilution high resolution mass spectrometry (GC/ID-HRMS). Conditional logistic regression, Bayesian kernel machine regression (BKMR), and weighted quantile sum (WQS) regression were employed to estimate the association between single PCB congeners as well as their mixture and PTC.

RESULTS

Four PCB congeners (PCB-74, PCB-99, PCB-105, PCB-118) had significant associations and dose-response relationships with increased risk of PTC in single congener models. When considering the effects from all measured PCBs and their potential interactions in the BKMR model, PCB-118 showed positive trends of association with PTC. Increased exposure to the PCB congeners as a mixturewas also associated with an increased risk of PTC in the WQS model, with the mixture dominated by PCB-118, followed by PCB-74 and PCB-99. One PCB congener, PCB-187, showed an inverse trend of association with PTC in the mixture analysis.

DISCUSSION

This study suggests that exposure to certain PCBs as well as a mixture of PCBs were associated with an increased risk of PTC. The observed association was mainly driven by PCB-118, and to a lesser extent by PCB-74 and PCB-99. The findings warrant further investigation.

Altered Sex Ratios in Offspring of U.S. Submariners Urban Legend or Fact - Do Submariners Have More Daughters?

INTRODUCTION

There is a widespread and long-held belief in the submarine community that submariners father more daughters than the general population. The U.S. Sex Ratio at birth (males/females) has remained around 1.05 since the early 2000s. Limited evidence exists that certain environmental exposures including chemicals, heavy metals, radiation and g-forces may influence sex ratio at birth. A reduction in male births in a population has been associated with lower male fertility. A 1970 single site study showed a higher ratio of female offspring in personnel serving aboard U.S. Navy nuclear submarines than the general population. A 2004 study concluded that this was probably not true. However, this study was small, and did not evaluate the difference between children conceived during sea duty versus shore duty. They did note a higher chance of female offspring correlated with a longer time in the community, as well as an increased ratio in sonar technicians. These findings warrant further investigation.

METHODS

An electronic survey was e-mailed to submariners, after receiving required IRB and Navy approvals. Participants were asked birth year, year they entered submarine service, and how many children they had. For each child they were asked sex, child's birth year, mother's birth year, and whether they were on sea duty or shore duty at the time of conception. Those who were on sea duty at the time of conception were asked what their job was, where they were stationed and what type of submarine they were on. Those who were on shore duty at the time of conception were asked whether they were in contact with submarines on a regular basis, whether they were officer or enlisted, and what region they were stationed in for shore duty.

RESULTS

Four thousand eight hundred responses were received with a total of 6,958 children included in the analysis. Respondents had a SR of 0.95 compared to 1.05 U.S. population in 2015 (p < 0.0001). Submariners on sea duty had a SR of 0.88 compared to 1.02 on shore duty (p = 0.007). Those who had regular submarine contact on shore duty had a SR of 0.72 compared to 1.17 in those who did not (p < 0.001). Geographical location during shore duty did show differences that were statistically significant (p = 0.018). Geographical location during sea duty did not show significant differences. No significant differences were seen for paternal age, maternal age, job during sea duty, type of submarine assigned to or time in community.

CONCLUSION

The submariners surveyed reported greater numbers of daughters than the general population, especially when on sea duty or in regular contact with submarines during shore duty. Further study should be done to confirm results and explore possible etiologies of differences in sex ratio.

Is Vitamin D Level at Melanoma Diagnosis Associated With Stage Of Tumor? An Observational Study of Melanoma Patients Living in a High Ultraviolet Radiation Environment

OBJECTIVES

This study will assess the relationship between vitamin D concentration at melanoma diagnosis and melanoma tumor characteristics, in individuals in a high ultraviolet radiation (UVR) environment.

METHODS

We aim to recruit 600 recently diagnosed melanoma patients from Queensland, Australia, a high UVR location with one of the world's highest melanoma incidence rates. Patients are recruited through general practitioner, skin cancer specialist, dermatological and hospital-based practices. As close as possible to diagnosis, participants provide a blood sample for vitamin D analysis and have their sun exposure/sun protection behavior, melanoma risk factors and dietary vitamin D intake assessed by questionnaire and phone interview. Details of tumor pathology, including tumor level, thickness, and ulceration, are abstracted from cancer registry records. Here, we describe the study methods and present preliminary findings from early participants.

RESULTS

As of December 2017, we have recruited 128 participants (48% male, mean age 60.2 years, mean Breslow thickness 0.63 mm).

CONCLUSIONS

When complete, this study will give insights into the association between vitamin D at diagnosis and melanoma tumor characteristics whilst adjusting for recent sun exposure and sun protection use. This study may impact military sun exposure and nutrition policies as vitamin D may play a role in melanomagenesis.

Skin cancer in the military: A systematic review of melanoma and nonmelanoma skin cancer incidence, prevention, and screening among active duty and veteran personnel

BACKGROUND

Occupational sun exposure is a well-studied risk factor for skin cancer development, but more work is needed to assess melanoma and nonmelanoma skin cancer risk among US military personnel to improve education and screening efforts in this population.

OBJECTIVE

To conduct an extensive review of skin cancer risks for US military personnel to inform preventive education, diagnosis, and treatment efforts to better protect these individuals from future skin cancer development.

METHODS

A systematic review of published studies on the subject of melanoma and nonmelanoma skin cancer in military personnel was conducted.

RESULTS

A total of 9 studies describing skin cancer incidence in the US military were identified, with 4 studies specific to melanoma. The study findings reveal an increased risk for melanoma associated with service in the military or prisoner of war status. Service in tropical environments was associated with an increased incidence of both melanoma and nonmelanoma skin cancer among World War II soldiers. Two studies found that increased melanoma risk was also branch dependent, with the highest rates among the United States Air Force. Several of the reviewed studies implicated increased sun exposure during military service and lack of sufficient sun protection as the causes of higher rates of skin cancer among US military and veteran populations as compared with among the nonmilitary population in the United States.

LIMITATIONS

The reviewed articles have variable results; a prospective randomized controlled trial would be helpful to develop interventions that mitigate skin cancer risk in the US military.

CONCLUSION

This review identifies an abundance of evidence for an increased risk for skin cancer development among US active duty and veteran populations.

Thyroid cancer incidence among active duty U.S. military personnel, 1990-2004

BACKGROUND

Increases in thyroid papillary carcinoma incidence rates have largely been attributed to heightened medical surveillance and improved diagnostics. We examined papillary carcinoma incidence in an equal-access health care system by demographics that are related to incidence.

METHODS

Incidence rates during 1990-2004 among white and black individuals aged 20 to 49 years in the military, and the general U.S. population were compared using data from the Department of Defense's Automated Central Tumor Registry and the National Cancer Institute's Surveillance Epidemiology and End Results (SEER-9) program.

RESULTS

Incidence was significantly higher in the military than in the general population among white women [incidence rate ratio (IRR) = 1.42; 95% confidence interval (CI), 1.25-1.61], black women (IRR = 2.31; 95% CI, 1.70-2.99), and black men (IRR = 1.69, 95% CI, 1.10-2.50). Among whites, differences between the two populations were confined to rates of localized tumors (women: IRR = 1.73, 95% CI, 1.47-2.00; men: IRR = 1.51, 95% CI, 1.30-1.75), which may partially be due to variation in staging classification. Among white women, rates were significantly higher in the military regardless of tumor size and rates rose significantly over time both for tumors ≤ 2 cm (military: IRR = 1.64, 95% CI, 1.18-2.28; general population: IRR = 1.55, 95% CI, 1.45-1.66) and > 2 cm (military: IRR = 1.74, 95% CI, 1.07-2.81; general population: IRR = 1.48, 95% CI, 1.27-1.72). Among white men, rates increased significantly only in the general population. Incidence also varied by military service branch.

CONCLUSIONS

Heightened medical surveillance does not appear to fully explain the differences between the two populations or the temporal increases in either population.

IMPACT

These findings suggest the importance of future research into thyroid cancer etiology.

Applications of polychlorinated biphenyls

BACKGROUND, AIM, AND SCOPE

In the 50 years or so that polychlorinated biphenyls (PCBs) were manufactured in the USA and elsewhere, they were widely used in numerous applications because of their desirable properties. The purpose of this paper is to review and summarize in one place the factual information about the uses of PCBs, as well as to correct some misconceptions that have arisen over the years. The focus is on applications in the USA for which there is ample documentation. However, use patterns were probably similar worldwide.

MATERIALS AND METHODS

Review.

RESULTS

PCBs were used primarily as electrical insulating fluids in capacitors and transformers and also as hydraulic, heat transfer, and lubricating fluids. PCBs were blended with other chemicals as plasticizers and fire retardants and used in a range of products including caulks, adhesives, plastics, and carbonless copy paper. In the USA, PCBs were manufactured from 1929 through mid-1977, although many products remained in service for decades after the manufacture of PCBs was terminated. This article reviews the historic uses of PCBs in the USA and discusses, where possible, the relative sales volumes. Especially with smaller volume, military, and third-party uses, documenting a use and/or differentiating between a commercial use and an experimental test batch is not possible.

DISCUSSION

A major contribution of this paper is to differentiate reported commercial applications of PCBs that can be documented from those which cannot. Undocumented uses may include actual minor uses as well as reported applications that are unlikely ever to have been commercialized.

Melanoma incidence rates among whites in the U.S. Military

BACKGROUND

The U.S. Military and general populations may differ in the exposure to sunlight and other risk factors for melanoma and therefore the incidence rates of melanoma may be different in these two populations. However, few studies have compared melanoma incidence rates and trends over time between the military and the general population.

METHODS

Melanoma incidence rates from 1990 to 2004 among white active-duty military personnel and the general U.S. population were compared using data from the Department of Defense Automated Central Tumor Registry and the National Cancer Institute Surveillance, Epidemiology, and End Results program.

RESULTS

Age-adjusted melanoma rates overall were significantly lower in the military than in the general population; the incidence rate ratio was 0.75 for men and 0.56 for women. Age-specific rates, however, were significantly lower among individuals younger than 45 years, but significantly higher among those 45 years or older (P < 0.05). Melanoma incidence increased from 1990-1994 to 2000-2004 in both populations, with the most rapid increase (40%) among younger men in the military. Melanoma incidence rates also varied by branch of military service; rates were highest in the air force.

CONCLUSION

These results suggest that melanoma incidence rate patterns differ between the military and the general population.

IMPACT

Further studies of risk factors for melanoma in the military are needed to explain these findings.