Carine J. Sakr

Cross-sectional Study of Lipids and Liver Enzymes Related to a Serum Biomarker of Exposure (ammonium perfluorooctanoate or Apfo) as Part of a General Health Survey in a Cohort of Occupationally Exposed Workers

Objective: To examine the relationship between serum perfluorooctanoate (PFOA), a biomarker of ammonium perfluorooctanoate (APFO) exposure, and lipids and liver enzymes in a cross-sectional study among workers with potential occupational exposure to APFO. Methods: We conducted a cross-sectional study of 1025 active workers with potential exposure to APFO using linear regression to examine the relationship between PFOA and selected outcomes from a standard metabolic health screening survey, emphasizing lipids and liver enzymes. Results: Most outcome parameters were within normal limits. After adjusting for potential confounders, we observed a modest but statistically significant, positive relationship between serum PFOA and total cholesterol, low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), and gamma glutamyl aminotransferase (GGT). No associations were seen for high-density lipoprotein (HDL) or bilirubin; associations with AST (aspartate aminotransferase) and ALT (alanine transpeptidase) did not reach statistical significance. Conclusions: Our findings indicate a modest positive association of PFOA on some lipid parameters and a need for follow-up studies.

Longitudinal study of serum lipids and liver enzymes in workers with occupational exposure to ammonium perfluorooctanoate.

Objective: To examine the relationship between serum perfluorooctanoate (PFOA), a biomarker of ammonium perfluorooctanoate exposure, and lipids and liver enzymes. Methods: We conducted a longitudinal study on 454 workers and used mixed models to examine the relationship between serum PFOA and lipids and liver enzymes. Results: One part per million (ppm) increase in serum PFOA was associated with a 1.06 mg/dL increase in total cholesterol, but was not associated with changes in triglycerides or other lipoproteins, after adjusting for potential confounders. Serum PFOA was also associated with total bilirubin (0.008 mg/dL decline/ppm) and serum aspartate aminotransferase (0.35 units increase/ppm) but not with the other liver enzymes. Conclusions: These medical surveillance data collected on workers for up to 25 years contributes useful information on the effects of ammonium perfluorooctanoate exposure on human liver and lipid chemistry.

Ischaemic heart disease mortality study among workers with occupational exposure to ammonium perfluorooctanoate

Objectives: Ammonium perfluorooctanoate (APFO) is a biopersistent surfactant used in the manufacture of several types of fluoropolymers. Based on previous findings of increased serum lipid levels associated with exposure to APFO, we evaluated ischaemic heart disease (IHD) mortality in a cohort of occupationally exposed workers. Methods: Relative risks (RR) were estimated from exposure–response analyses of cumulative exposure measures using proportional hazards regression models. Results: 239 IHD deaths have occurred in the cohort of 4747 workers with work histories from 1948 through 2002. RR estimates indicate no statistically significant increased mortality risk for IHD associated with estimated cumulative exposure. We observed a positive trend only at an exposure lag of 10 years. This finding was not reproduced in other 5-year exposure lags and was attenuated when different cutpoints for exposure categorisation were used. Conclusion: This exposure–response study shows no convincing evidence of increased IHD mortality risk for APFO-exposed workers at this plant. Further studies evaluating the incidence of IHD are being conducted.

Mortality among workers exposed to acrylonitrile in fiber production: an update.

Objective: The investigation updates the mortality experience through 2002 for a cohort of workers exposed to acrylonitrile (AN). Methods: Standardized mortality ratios (SMR) were estimated based on two reference populations: the US population and a regional employee population. Exposure–response analyses were conducted using Cox regression models for cumulative and mean intensity exposure measures. Results: In the cohort of 2548 workers, 839 deaths have occurred with 91 deaths due to respiratory system cancer. Most standardized mortality ratio estimates are at or near no-effects levels. Hazard ratio (HR) estimates indicate no increased mortality risk for respiratory system cancer (adjusted HR = 0.96, 95% confidence interval: 0.74, 1.25). Conclusions: In summary, no mortality outcome of a priori interest, principally respiratory system cancer, is associated with increased AN exposure among fiber production workers over five decades of follow-up.

Reproductive outcomes among male and female workers at an aluminum smelter.

Objectives: Several adverse pregnancy outcomes were reported among female laboratory workers in a North American aluminum smelter. To determine whether these outcomes were associated with any occupational exposure at the plant, a cross-sectional survey was undertaken. Methods: Rates of miscarriage, premature singleton birth, and major congenital anomaly occurring during employment were compared with a reference group comprised of all pregnancies that occurred before employment. Results: Among female workers, the excess of congenital anomalies among female laboratory workers that defined the initial cluster was observed, but no specific pattern was found. Conclusions: On the basis of these analyses, the increase in congenital anomalies could not be attributed to occupational exposures at the smelter nor could potential exposure likely explain the diverse anomalies described.

Evaluation of safety climate and employee injury rates in healthcare

Objectives Safety climates that support safety-related behaviour are associated with fewer work-related injuries, and prior research in industry suggests that safety knowledge and motivation are strongly related to safety performance behaviours; this relationship is not well studied in healthcare settings. Methods We performed analyses of survey results from a Veterans Health Administration (VHA) Safety Barometer employee perception survey, conducted among VHA employees in 2012. The employee perception survey assessed 6 safety programme categories, including management participation, supervisor participation, employee participation, safety support activities, safety support climate and organisational climate. We examined the relationship between safety climate from the survey results on VHA employee injury and illness rates. Results Among VHA facilities in the VA New England Healthcare System, work-related injury rate was significantly and inversely related to overall employee perception of safety climate, and all 6 safety programme categories, including employee perception of employee participation, management participation, organisational climate, supervisor participation, safety support activities and safety support climate. Conclusions Positive employee perceptions of safety climate in VHA facilities are associated with lower work-related injury and illness rates. Employee perception of employee participation, management participation, organisational climate, supervisor participation, safety support activities and safety support climate were all associated with lower work-related injury rates. Future implications include fostering a robust safety climate for patients and healthcare workers to reduce healthcare worker injuries.

Iraq/Afghanistan-Era Veterans with Back Pain: Characteristics and Predictors of Compensation and Pension Award

Approximately 440,000 U.S. Veterans receive compensation for back and/or neck conditions. Veterans Benefits Administration (VBA) criteria state that back compensation determinations are based on impaired back function and not comorbidity or lifestyle, but whether compensation is based solely on consideration of the lumbosacral region is unknown. In this study, we conducted a cross-sectional analysis of medical chart data from 178 post-9/11 Veterans applying for service connection for back pain in fiscal year 2012 at the Department of Veterans Affairs Connecticut Healthcare System. Altogether, 62% were noted to have impairment of back functioning and 74% were awarded compensation. Rates of comorbidities (obesity, depression, smoking, and illicit drug use) were high. In multivariate models predicting compensation awarded, only having an impaired back was associated with service-connected compensation. Pain was associated with extent of service connection, but this relationship was fully mediated by functional back impairment. No other measure (including work status) significantly predicted compensation. In summary, service connection was largely based on functional impairment, as called for in VBA criteria. Although pain and comorbidities undoubtedly affect day-to-day functioning, these factors were not independently related to service connection. Veterans present with many remediable conditions, and the service-connection evaluation may be an opportunity to engage them in treatment.