Styrene and breast cancer incidence in Texas: a comment on an ecological association.
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Biomedical subjects
Publications and source records attributed to Shan P Tsai.
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The extent of interaction between smoking and diabetes has been under-appreciated. Smokers had more diabetes, and when diabetes patients smoke, the combined mortality effect was greater than either the addition or multiplication of these two medical problems. Patients seen in the office are usually more interested in reducing blood glucose than in quitting smoking, and yet, smoking caused mortality risks, at a magnitude similar to or more than diabetes. The concept of "glucose equivalent of smoking" was developed to direct more attention to smoking in clinical management. Based on the follow-up observations from a large Asian cohort, the risk of an individual who smokes, from all-cause mortality, was found to be equivalent to an elevation of blood glucose by an average of 41mg/dl for the cohort in general and 68mg/dl for the diabetes in particular. By relating the message of smoking hazards in terms of "glucose equivalent", clinicians will be more alerted to counsel and patients will be more likely to quit. Appreciating this concept has a potential to change the paradigm of diabetes management, to bridge the clinical disconnect between the two, and to provide new ammunition for the diabetes epidemic in Taiwan.
BACKGROUND: Although obesity is an established risk factor for coronary heart disease and stroke mortality, its role as a risk factor for other causes of death has not been extensively investigated, particularly in an industrial population. METHODS: This prospective mortality study included 20 years of follow up of middle-aged industrial workers (n = 7139) at Shell Oil Company's manufacturing and research facilities. Baseline health risk factor data as of December 31, 1983, and mortality data as of December 31, 2003, were extracted from the company's Health Surveillance System. Relative risks (RRs) for selected causes of death by body mass index (BMI) category were calculated using the Cox proportional hazards model adjusted for age, sex, and smoking status as well as other potential risk factors, ie, cholesterol, hypertension, and fasting blood glucose. RESULTS: Compared with employees with BMI between 18.5 and 24.9 kg/m, those with BMI of 30 kg/m or greater had a statistically increased RR (adjusted for age, sex, and smoking status) for all causes (RR, 1.25; 95% confidence interval [CI] = 1.03-1.51), coronary heart diseases (RR, 2.29; 95% CI = 1.50-3.50), cardiovascular diseases (RR, 2.22; 95% CI = 1.51-3.27), diabetes (RR, 16.97; 95% CI = 2.11-136.44), and accidental deaths (RR, 2.64; 95% CI = 1.23-5.66). After adjusting for additional covariates, coronary heart diseases and cardiovascular diseases remained statistically significant. CONCLUSIONS: Obesity was associated with increased death rates for all causes, cardiovascular diseases, diabetes, and all accidents. Overweight individuals had a statistically lower cancer rate. Death rates for lung cancer and respiratory disease were lower among overweight/obese employees but did not reach statistical significance. Reductions of employee obesity can be an effective means of reducing these causes of death.
BACKGROUND: An inhouse disability management program was implemented to reduce nonoccupational absences in a petrochemical corporation. The program was administered by full-time certified, corporate-based case managers and nine manufacturing location nurses. METHODS: Employees were required to report all absences on the first day and again on the fourth workday of absence. A medical certification form was required for absences of 4 or more working days. Extended absences were actively managed. An Internet-based case management tool, Medgate, was used as a primary management tool. RESULTS: Results were compared with the previous year among the target population and with company business units not participating in the program. The program resulted in a 10% reduction in total absence days per employee (6.9 to 6.2) compared with the previous year, whereas business units not using the program had an 8% increase (5.5 to 5.9). This disability management program resulted in a more than four to one return on investment based on direct expenditures and cost savings in terms of reduced absence days. CONCLUSIONS: The inhouse disability management program was successful by absence duration, employee satisfaction, and return on investment criteria.
OBJECTIVE: To assess whether early retirement is associated with better survival. DESIGN: Long term prospective cohort study. SETTING: Petroleum and petrochemical industry, United States. SUBJECTS: Past employees of Shell Oil who retired at ages 55, 60, and 65 between 1 January 1973 and 31 December 2003. MAIN OUTCOME MEASURE: Hazard ratio of death adjusted for sex, year of entry to study, and socioeconomic status. RESULTS: Subjects who retired early at 55 and who were still alive at 65 had a significantly higher mortality than those who retired at 65 (hazard ratio 1.37, 95% confidence interval 1.09 to 1.73). Mortality was also significantly higher for subjects in the first 10 years after retirement at 55 compared with those who continued working (1.89, 1.58 to 2.27). After adjustment, mortality was similar between those who retired at 60 and those who retired at 65 (1.06, 0.92 to 1.22). Mortality did not differ for the first five years after retirement at 60 compared with continuing work at 60 (1.04, 0.82 to 1.31). CONCLUSIONS: Retiring early at 55 or 60 was not associated with better survival than retiring at 65 in a cohort of past employees of the petrochemical industry. Mortality was higher in employees who retired at 55 than in those who continued working.
BACKGROUND: The implementation of worksite smoking policies has shown significant effects on reducing employees' smoking consumption and protecting non-smoking workers. However, there are no data about workplace smoking policies in Taiwan. The purpose of this study was to document the status of worksite smoking policies in Taiwan and its potential impact on employees' smoking behaviours. METHODS: A two-stage investigation was conducted. The first stage was to examine the current status of workplace smoking policies and the second was to evaluate the relationship between workplace smoking policies and employees' smoking behaviours. After two follow-ups in each stage, 264 companies and 1141 employees returned their questionnaires. RESULTS: Workplace smoking policies were associated with types of businesses and size of workplaces. Only approximately half of manufacturing and service companies have implemented a prohibitive smoking policy. Large facilities (>750 employees) were more likely to implement a prohibitive policy (57%). Employees in workplaces with a prohibitive policy had lower prevalence of smoking and cigarette consumption, and less exposure to passive smoking. Although most smokers agreed with banning smoking in their work environment, no difference in interest in participating in cessation programs was found. CONCLUSIONS: Significant associations were found between workplace smoking policies and employees' smoking behaviours. Results of the study provide basic information for designing more refined smoking policies in the workplace in Taiwan.
Complete blood counts (CBC) have been recognized as an easy and readily available screen for hematotoxicity following occupational exposure to 1,3-butadiene. This study evaluated hematology data from employees who have ever participated in the Shell Butadiene Medical Surveillance Program (BMSP), compared with employees who have not participated. This study examined potential hematopoietic toxicity in relation to the occupational exposures at two Shell facilities. This study included 404 employees who participated in the BMSP, with mean butadiene exposure (TWA-8, TWA-10, and TWA-12 together) of 4.55 ppm from 1979-1996 and 0.25 ppm from 1997-2003, and 773 comparison employees. The comparison group included employees not participating in either the benzene or butadiene surveillance programs. Abnormality of six CBC parameters, including white blood cell count, red blood cell count, lymphocyte count, hemoglobin concentration, mean corpuscular volume and platelet count, and the adjusted mean values of these parameters in the exposed group were compared with those of the comparison group. We found no significantly increased abnormality for any hematology parameter among exposed employees. The adjusted mean values (adjusted for age, sex, race, length of time between first and last exam, current smoking status, and first exam value) of the exposed employees were similar to those in the comparison group. At current occupational exposure levels for 1,3-butadiene, there is no evidence of adverse hematological effects observed in this study. These findings are consistent with results of three similar studies in the literature.
BACKGROUND: Illness absence in a working population is a complex phenomenon and can be influenced by many factors, such as age, gender, and personal health risk factors. The current study used prospectively collected employee health risk and morbidity data to examine illness absence patterns for a working population and to quantify the impact of selected health risk factors on employee illness absence. METHODS: The study population consisted of 2550 regular employees working at a Texas petrochemical facility. Morbidity data were extracted from the company's Health Surveillance System, and records of absences were derived from personnel and payroll systems. The morbidity frequency rate and average duration of absence per employee per year were calculated by age, gender, and selected health risk factors, including smoking, body mass index, cholesterol, triglycerides, hypertension, and fasting glucose. RESULTS: Morbidity frequency rates and average duration of absence increased with age and with the presence of health risk factors. The absence frequency rate increased with an increase in the number of risk factors present from no risk factors (11.8 per 100 employees) to four or more risk factors (32.3 per 100 employees). The number of workdays lost also increased with the number of risk factors present, with the least number of workdays lost by employees with zero risk factors (4.1 day), followed by one (6.4 days), two (8.8 days), three (9.3 days), and four or more risk factors (12.6 days). CONCLUSIONS: The impact of employee health risk factors has been shown in this study to be associated with absence frequency and duration of absence. Reduction in employee health risk factors can be an effective means of improving employees' health and increasing a company's productivity.
PURPOSE: The purpose of this study is to determine the incidence of cancer among employees at two petrochemical facilities in south Louisiana, and to compare their cancer rates to those of the general population of south Louisiana. METHODS: Records on 4639 active and former employees and retirees from the two plants were linked to the Louisiana Tumor Registry (LTR) database by LTR staff to ascertain incident cases of cancer. Standardized incidence ratios (SIRs) were then calculated using the south Louisiana population as the comparison and adjusted for age, race, and time period. RESULTS: There was a significant 16% deficit of overall cancer cases for males in this cohort (SIR=0.84; 95% CI, 0.74-0.95). The only significantly elevated SIR in males was for cancer of the bone and joint (SIR=6.89; 95% CI, 1.42-20.1). This result was based on three non-fatal cases of bone cancer with different histologies, occurring in different parts of the body. These cases worked in different units of one plant. Significant deficits were seen for lung cancer, non-Hodgkin's lymphoma, and cancer of the oral cavity and pharynx. Cancer incidence among 719 female employees was non-significantly increased (SIR=1.24; 95% CI, 0.81-1.82). Breast cancer accounts for the excess (SIR=1.46; 95% CI, 0.73-2.61). Seventy percent of the breast cancer cases worked in an office setting. CONCLUSIONS: This study found little evidence of any association between cancer incidence and employment at these two petrochemical facilities. The increased incidence of bone cancer is unlikely to be due to occupational exposures. The non-significant excess of breast cancer may be due to early detection or other important unmeasured confounders, such as certain reproductive factors.
Historically, complete blood counts (CBCs) have been recognized as an easy and readily available screen for hematotoxicity following occupational exposure to benzene. The purpose of this study is to evaluate hematology data from employees who have ever participated in the Shell Benzene Medical Surveillance Program (BMSP) compared to employees who have not participated and to examine the sensitivity of CBCs to detect hematological changes in a low-exposure occupational setting. This large study included 1200 employees who participated in the BMSP, with mean benzene exposure (TWA-8) of 0.60 ppm from 1977 to 1988 and 0.14 ppm since 1988, and 3227 comparison employees. The comparison group included employees not enrolled in either the benzene or butadiene surveillance programs. Abnormality of six CBC parameters and the adjusted mean values of these parameters in the exposed group were compared with that of the comparison group. We found no increased abnormality for any hematology parameter among exposed employees. The adjusted mean values (adjusted for age, sex, race, length of time between first and last exam, and current smoking status) of the exposed employees were similar to those in the comparison group. At current occupational exposure levels for benzene, no evidence of adverse hematological effects was observed in this study. These results raise the question of whether annual CBC surveillance for benzene-exposed workers has adequate sensitivity to detect meaningful hematological changes due to low-level exposures.
Cigarette smoking is one of the most serious health problems in Taiwan. Although the Taiwanese government passed a Tobacco Hazard Control Act in 1997, it is not fully applicable to the workplace. The purpose of the study was to review workplace smoking prevalence and policies, and to discuss the opportunities and challenges of implementing workplace smoking policies in Taiwan. Results show that smoking prevalence in the workplace in Taiwan is high, particularly among males, ranging from 38 to 68%. More than 75% of smokers in Taiwan smoke in the workplace. The percentage of workplaces implementing restrictive smoking policies in Taiwan is low, particularly in small-sized workplaces. The Tobacco Hazard Control Act in Taiwan has not been strongly enforced in public places, let alone in private companies. Several constructive suggestions are presented in the study. For example, establishing workplace smoking policies, informing employers that second-hand smoke is a human carcinogen, providing financial support for employers to initiate cessation programs, and modifying the current Tobacco Hazard Control Act, etc.
BACKGROUND: Similar to the general population in Taiwan, the health of aborigines has steadily improved over the last 30 years, but the gap remains wide, especially in males, despite an infusion of substantial medical resources. The objectives of this study are to quantify the contribution of major causes of death to the gap in life expectancy and to propose initiatives to bridge the health gap between aborigines and the general population. METHODS: This study included residents (slightly over 200000) from 30 'aboriginal townships' in Taiwan. The gap in life expectancy between aborigines and the general population was analysed by decomposing these gaps according to major causes of deaths. This analysis quantifies the contribution of different causes of deaths to the gap in life expectancy between the two populations. RESULTS: The overall mortality of aborigines in these townships was approximately 70% higher than the respective male and female general populations over the past 30 years. Mortality from infectious disease, cirrhosis of the liver, accidents, and suicide are substantially higher than the general population. The gap in life expectancy at birth in males was 8.5 years during 1971-1973, increasing to 13.5 years by 1998-2000, however, the gap in females remained relatively stable (8.0 years and 8.4 years, respectively). Of the 13.5-year difference in life expectancy in males, the differential mortality from diseases of the digestive system (mainly due to cirrhosis of the liver), accidents (from both motor vehicle and non-motor vehicle accidents), and infectious and parasitic disease contributed half (50%) of the gap in life expectancy. In females, the above primarily preventable causes of deaths accounted for 41% of the life expectancy gap. CONCLUSIONS: Based on the findings of this study, we suggest that future focus should be in the area of primary prevention in order to reduce the incidence of infectious and parasitic diseases, liver cirrhosis, and accidents.
This work presents 10 years of experience using an Integrated Workers' Compensation Claims Management System that allows safety professionals, adjusters, and selected medical and nursing providers to collaborate in a process of preventing accidents and expeditiously assessing, treating, and returning individuals to productive work. The hallmarks of the program involve patient advocacy and customer service, steerage of injured employees to a small network of physicians, close follow-up, and the continuous dialogue between parties regarding claims management. The integrated claims management system was instituted in fiscal year 1992 servicing a population of approximately 21,000 individuals. The system was periodically refined and by the 2002 fiscal year, 39,000 individuals were managed under this paradigm. The frequency of lost-time and medical claims rate decreased 73% (from 22 per 1000 employees to 6) and 61% (from 155 per 1000 employees to 61), respectively, between fiscal year 1992 and fiscal year 2002. The number of temporary/total days paid per 100 insureds decreased from 163 in fiscal year 1992 to 37 in fiscal year 2002, or 77%. Total workers' compensation expenses including all medical, indemnity and administrative, decreased from $0.81 per $100 of payroll in fiscal year 1992 to $0.37 per $100 of payroll in fiscal year 2002, a 54% decrease. More specifically, medical costs per $100 of payroll decreased 44% (from $0.27 to $0.15), temporary/total, 61% (from $0.18 to $0.07), permanent/partial, 63% (from $0.19 to $0.07) and administrative costs, 48% ($0.16 to $0.09). These data suggests that workers' compensation costs can be reduced over a multi-year period by using a small network of clinically skilled health care providers who address an individual workers' psychological, as well as physical needs and where communication between all parties (e.g., medical care providers, supervisors, and injured employees) is constantly maintained. Furthermore, these results can be obtained in an environment in which the employer pays the full cost of medical care and the claimant has free choice of medical provider at all times.