EMPLOYMENT AND EXPOSURES IN THE PETROLEUM REFINING AND PETROCHEMICAL INDUSTRIES AND THE RISK OF LUNG CANCER (EPIDEMIOLOGY, ASSESSMENT)

This dissertation addresses the risk of lung cancer associated with occupational exposures in the petroleum refining and petrochemical industries. Earlier epidemiologic studies of this association did not adjust for cigarette smoking or have specific exposure classifications. The Texas EXposure Assessment System (TEXAS) was developed with data from a population-based, case-comparison study conducted in five southeast Texas counties between 1976 and 1980. The Texas Exposure Assessment System uses job and process categories developed by the American Petroleum Institute, as well as time-oriented variables to identify high risk groups.^ An industry-wide, increased risk for lung cancer was associated with jobs having low-level hydrocarbon exposure that also include other occupational inhalation exposures (OR = 2.0--adjusted for smoking and latency effects). The prohibition of cigarette smoking for jobs with high-level hydrocarbon exposure might explain part of the increased risk for jobs with low-level hydrocarbon exposures. Asbestos exposure comprises a large part of the risk associated with jobs having other inhalation exposures besides hydrocarbons. Workers in petroleum refineries were not shown to have an increased, occupational risk for lung cancer. The increased risk for lung cancer among petrochemical workers (OR = 3.1--smoking and latency adjusted) is associated with all jobs that involve other inhalation exposure characteristics (not only low-level hydrocarbon exposures). Findings for contract workers and workers exposed to specific chemicals were inconclusive although some hypotheses for future research were identified.^ The study results demonstrate that the predominant risk for lung cancer is due to cigarette smoking (OR = 9.8). Cigarette smoking accounts for 86.5% of the incident lung cancer cases within the study area. Workers in the petroleum industry smoke significantly less than persons employed in other industries (p << 0.001). Only 2.2% of the incident lung cancer cases may be attributed to petroleum industry jobs; lifestyle factors (e.g., nutrition) may be associated with the balance of the cases. The results from this study also suggest possible high risk time periods (OR = 3.9--smoking and occupation adjusted). Artifacts in time-oriented findings may result because of the latency interval for lung cancer, secular peaks in age-, sex-specific incidence rates, or periods of hazardous exposures in the petroleum industry. ^

Pre-employment drug testing among job applicants at a Texas tertiary level pediatric hospital: 1992--2006

This study is a retrospective longitudinal study at Texas Children's Hospital, a 350-bed tertiary level pediatric teaching hospital in Houston, Texas, for the period 1990 to 2006. It measured the incidence and trends of positive pre-employment drug tests among new job applicants At TCH. ^ Over the study period, 16,219 job applicants underwent pre-employment drug screening at TCH. Of these, 330 applicants (2%) tested positive on both the EMIT and GC/MS. After review by the medical review officer, the number of true drug test positive applicants decreased to 126 (0.78%). ^ According to the overall annual positive drug test incidence rates, the highest overall incidence was in 2002 (14.71 per 1000 tests) and the lowest in 2004 (3.17 per 1000 tests). Despite a marked increase in 2002, over the 15-year study period the overall incidence tended to decrease. Incidence rates and trends of other illegal drugs are further discussed in the study. And in general, these incidence rates also decline in the study period. In addition to that, we found the overall, positive drug tests were more common in females than in males (55.5% versus 44.4%). ^

Employment outcomes in liver transplant recipients: A policy analysis

Liver transplantation is a widely accepted treatment for end stage liver disease. Research has shown that people with end-stage liver disease experience improved survival and health-related quality of life after transplantation. However, the unemployment rate among liver transplant recipients remains high. The reasons for this were the subject of a study that was used as the primary dataset for this policy analysis. According to the primary data and background supporting data, many transplant recipients remain unemployed for fear of losing needed healthcare and disability benefits. When employment is considered as a health outcome, it is important in an era of evidence based medicine to ensure that healthcare interventions such as liver transplantation produce improved health outcomes. Therefore, the high unemployment rate among liver transplant recipients is a poor health outcome that should be addressed. In this policy analysis, it is proposed that policy might affect this outcome. The problem of unemployment after liver transplantation is structured and policies affecting the problem are evaluated according to the validated criteria - Effectiveness, Equity, Efficiency, and Feasibility. A policy solution is proposed, evaluated, and ultimately recommended to effectively address the problem, to make healthcare coverage more equitable for liver transplant recipients, and to provide a more cost-effective healthcare coverage model during this time of healthcare crisis.^

Association of part-time employment and sexual risk-taking behaviors among middle school students

Background. Previous research shows inconsistent results as to the association between part-time employment and sexual behavior among younger teens. Studies of older teens cannot be generalized to younger teens because of the wide differences in types of work performed, nature of work environments, and work intensity. Objective. Examine the relationship between part-time employment and sexual behavior in a cross-sectional sample of public middle school students in Houston, Texas. Methods . The study presents a secondary analysis of data from the It’s Your Game…Keep it Real baseline data collection (11/2004–1/2005). It’s Your Game… is an intervention program for middle school students designed to prevent Sexually Transmitted Infections. Statistical analysis. Univariate and multivariate logistic regression analyses were conducted to examine the association between part-time employment and vaginal intercourse: (a) ever had sex; and (b) current sexual activity. Results. Overall, 13.2% of students worked for pay; male students were 1.5 times as likely as females to be working. Of all the students, 11.0% had had sexual intercourse; students who worked were 3 times more likely to be sexually experienced than those who did not. Among students who were sexually experienced, 67.0% were currently sexually active. After adjusting for the other covariates, Hispanic students were almost 3.6 times more likely to report current sexual activity compared to students in other racial/ethnic groups. In univariate analysis, students who worked 1-5 hrs/week were more likely to be sexually experienced than those not currently employed, and the likelihood increased with number of hours worked. There is a similar pattern in the multivariate model, but the odds ratios are too close for the evidence to be more than suggestive. Of sexually experienced students, students working 1-5 hrs/week were 2.7 times more likely to report current sexual intercourse than those not working; those working >5 hrs/week were 4.7 times more likely. The multivariate model showed a similar increase in likelihood, and adjustment for covariates increased these associations: students who worked 1-5 hrs/week were 3.6 times more likely to report current sexual intercourse, and students who worked >5 hrs/week were 4.5 times more likely, than students not currently employed.^

Factors related to employment among chronically mentally ill patients

A descriptive study of demographic and psychosocial factors believed to be associated with employment was carried out through face-to-face interviews with 417 chronically mentally-ill patients. Subjects had been hospitalized a minimum of two times for psychiatric treatment, had been discharged from at least one of these hospitalizations in the two years prior to the study, and were currently residing within a specific community mental health center catchment area in Texas. The study group ranged in age from 16 to 68 years and over one-half had chart diagnoses of schizophrenia.^ A structured interview was developed which addressed current employment status, length of current employment, job title of current or last job, and detailed work history for the prior five years. Four measures of social support were included in the interview. Each subject was asked to identify one recent work and one recent non-work situation which had been stressful or very demanding. A coping questionnaire was verbally administered to measure the ways in which subjects had coped with these specific stressful situations.^ Analysis of results revealed that 27 percent of the sample was gainfully employed at time of interview. Differences between the employed and unemployed groups were analyzed by t-test an chi square. The employed demonstrated significantly more weeks of employment in the prior five years than the unemployed. The current jobs of the employed required a significantly higher relationship to "things" or inanimate objects than the last jobs of the unemployed. Subjects diagnosed as schizophrenic were significantly less likely to be employed than subjects with other diagnoses.^ Employed subjects scored significantly higher on three of four measures of social support than unemployed subjects, including reported frequency of social group attendance and/or meetings with mental health professionals. Problem-focused coping was used significantly more by the employed than by the unemployed to deal with stressful situations in the work, but not the non-work, context. ^

A case-comparison interview study of brain tumors and employment in occupations with presumed electric and magnetic field exposures

Results from epidemiologic studies suggest that persons working in occupations with presumed electric and magnetic field (EMF) exposures are at increased risk of brain cancer. This study utilized data from a completed, population-based, interview case-control study of central nervous system (CNS) tumors and employment in the petrochemical industry to test the hypothesis that employment in EMF-related occupations increases CNS tumor risk. A total of 375 male residents of the Texas-Louisiana Gulf Coast Area, age 20 to 79, with primary neuroglial CNS tumors diagnosed during the period 1980-84 were identified. A population-based comparison group of 450 age, race and geographically matched males was selected. Occupational histories and potential risk factor data were collected via personal interviews with study subjects or their next-of-kin.^ Adjusted odds ratios were less than 1.0 for persons ever employed in an electrical occupation (OR = 0.65; 95% CI = 0.40-1.09) or whose usual occupation was electrical (OR = 0.76; 95% CI = 0.33-1.73). Relative risk estimates did not increase significantly as time since first employment or duration of employment increased. Examination of CNS tumor risk by high (OR = 0.80), medium (OR = 0.88) and low (OR = 0.45) exposure categories for persons whose usual occupation was electrical did not indicate a dose-response pattern. In addition, the mean age of exposed cases was not significantly younger than that for unexposed cases. Analysis of risk by probability of exposure to EMFs showed non-significant elevations in the adjusted odds ratio for definite exposed workers defined by their usual occupation (OR = 1.78; 95% CI = 0.70-4.51) and ever/never employed status (OR = 1.54; 95% CI = 0.17-4.91).^ These findings suggest that employment in occupations with presumed EMF exposures does not increase CNS tumor risk as was suggested by previous investigations. The results of this study also do not support the EMF-tumor promotion hypothesis. ^

Parental Employment and Home Visiting Program Service Delivery

Home visiting programs, which provide in-home services to disadvantaged families with young children, rest on the assumption that poor parents can be reached at home. Increased levels of maternal employment raise questions about this assumption. In this study, longitudinal data collected for a home visiting program evaluation were analyzed to assess whether employment patterns of parents who receive home visiting services reflect employment patterns of other poor mothers between 1995 and 2000. The study also addresses the relationship between maternal employment and home visiting service intensity. To effectively reach home visiting participants, service providers may need to modify service delivery practices.