Acute Bronchitis and Bronchiolitis Infection in Children with Asthma and Allergic Rhinitis: A Retrospective Cohort Study Based on 5,027,486 Children in Taiwan

This study evaluated the risks of childhood acute bronchitis and bronchiolitis (CABs) for children with asthma or allergic rhinitis (AR). Using insurance claims data of Taiwan, we identified, from children of ≤12 years old in 2000-2016, cohorts with and without asthma (N = 192,126, each) and cohorts with and without AR (N = 1,062,903, each) matched by sex and age. By the end of 2016, the asthma cohort had the highest bronchitis incidence, AR and non-asthma cohorts followed, and the lowest in the non-AR cohort (525.1, 322.4, 236.0 and 169.9 per 1000 person-years, respectively). The Cox method estimated adjusted hazard ratios (aHRs) of bronchitis were 1.82 (95% confidence interval (CI), 1.80-1.83) for the asthma cohort and 1.68 (95% CI, 1.68-1.69) for the AR cohort, relative to the respective comparisons. The bronchiolitis incidence rates for these cohorts were 42.7, 29.5, 28.5 and 20.1 per 1000 person-years, respectively. The aHRs of bronchiolitis were 1.50 (95% CI, 1.48-1.52) for the asthma cohort and 1.46 (95% CI, 1.45-1.47) for the AR cohort relative to their comparisons. The CABs incidence rates decreased substantially with increasing age, but were relatively similar for boys and girls. In conclusion, children with asthma are more likely to develop CABs than are children with AR.

Roles of Ambient Temperature and PM2.5 on Childhood Acute Bronchitis and Bronchiolitis from Viral Infection

Studies have associated the human respiratory syncytial virus which causes seasonal childhood acute bronchitis and bronchiolitis (CABs) with climate change and air pollution. We investigated this association using the insurance claims data of 3,965,560 children aged ≤ 12 years from Taiwan from 2006−2016. The monthly average incident CABs increased with increasing PM2.5 levels and exhibited an inverse association with temperature. The incidence was 1.6-fold greater in January than in July (13.7/100 versus 8.81/100), declined during winter breaks (February) and summer breaks (June−August). The highest incidence was 698 cases/day at <20 °C with PM2.5 > 37.0 μg/m3, with an adjusted relative risk (aRR) of 1.01 (95% confidence interval [CI] = 0.97−1.04) compared to 568 cases/day at <20 °C with PM2.5 < 15.0 μg/m3 (reference). The incidence at ≥30 °C decreased to 536 cases/day (aRR = 0.95, 95% CI = 0.85−1.06) with PM2.5 > 37.0 μg/m3 and decreased further to 392 cases/day (aRR = 0.61, 95% CI = 0.58−0.65) when PM2.5 was <15.0 μg/m3. In conclusion, CABs infections in children were associated with lowered ambient temperatures and elevated PM2.5 concentrations, and the high PM2.5 levels coincided with low temperature levels. The role of temperature should be considered in the studies of association between PM2.5 and CABs.

A cohort study evaluating the risk of stroke associated with long-term exposure to ambient fine particulate matter in Taiwan

BACKGROUND

Evidences have shown that the stroke risk associated with long-term exposure to particulate matter with an aerodynamic diameter of ≤2.5 μm (PM_2.5) varies among people in North America, Europe and Asia, but studies in Asia rarely evaluated the association by stroke type. We examined whether long-term exposure to PM_2.5 is associated with developing all strokes, ischemic stroke and hemorrhagic stroke.

METHODS

The retrospective cohort study consisted of 1,362,284 adults identified from beneficiaries of a universal health insurance program in 2011. We obtained data on air pollutants and meteorological measurements from air quality monitoring stations across Taiwan in 2010-2015. Annual mean levels of all environmental measurements in residing areas were calculated and assigned to cohort members. We used Cox proportional hazards models to estimate hazard ratio (HR) and 95% confidence interval (CI) of developing stroke associated with 1-year mean levels of PM_2.5 at baseline in 2010, and yearly mean levels from 2010 to 2015 as the time-varying exposure, adjusting for age, sex, income and urbanization level.

RESULTS

During a median follow-up time of 6.0 years, 12,942 persons developed strokes, 9919 (76.6%) were ischemic. The adjusted HRs (95% CIs) per interquartile range increase in baseline 1-year mean PM_2.5 were 1.03 (1.00-1.06) for all stroke, 1.06 (1.02-1.09) for ischemic stroke, and 0.95 (0.89-1.10) for hemorrhagic stroke. The concentration-response curves estimated in the models with and without additional adjustments for other environmental measurements showed a positively linear association between baseline 1-year mean PM_2.5 and ischemic stroke at concentrations greater than 30 μg/m³, under which no evidence of association was observed. There was an indication of an inverse association between PM_2.5 and hemorrhagic stroke, but the association no longer existed after controlling for nitrogen dioxide or ozone. We found similar shape of the concentration-response association in the Cox regression models with time-varying PM_2.5 exposures.

CONCLUSION

Long-term exposure to PM_2.5 might be associated with increased risk of developing ischemic stroke. The association with high PM_2.5 concentrations remained significant after adjustment for other environmental factors.

Mortality Experience in a Rapidly Developing Economy in Taiwan: Infant Mortality, Gender Gap, and Occupational Risks

Mortality data of Taiwan for 1981 through 1986 were analyzed using three different statistics in order to assess the role of environmental and lifestyle factors in causing mortality variations. Infant mortality rates from different geographic regions generally correlated well with overall mortality from all ages, suggesting that there are many common risk factors affecting the entire age range of the population. The mortality rates of tobacco-and alcohol-related causes of death and cancers were much higher in males than females. A number of cancer sites, including the lung, the liver, the stomach, and the nasopharynx, showed more than twofold excesses in males. In contrast, females had a tenfold excess of genital cancer and a 33% higher rate of diabetes. With rapid industrialization, occupational hazards played an increasing role in the development of cancer and other causes of death. During the study period, fishermen showed increased risk for cancers of the stomach, the esophagus, and the liver, while construction workers had an increased risk for cancer of the esophagus. Peasants and soldiers had an elevated suicide mortality. Among apprentices, fatal injuries were high. Findings from this study are useful in setting priorities for health and safety programs and directing efforts such as health education programs and other preventive strategies against disease.

Simulating the impact of changing trends in smoking and obesity on productivity of an industrial population: an observational study

OBJECTIVE

To estimate the impact of trends in smoking and obesity prevalence on productivity loss among petrochemical employees from 1980 to 2009.

METHODS

Smoking and obesity informations were collected during company physical examinations. Productivity loss was calculated as differential workdays lost between smokers and non-smokers, and obese and normal-weight employees.

RESULTS

During 1980-2009, smoking prevalence decreased from 32% to 17%, while obesity prevalence increased from 14% to 42%. In 1982, lost productivity from obesity was an estimated 43 days/100 employees, and for smoking, 65 days/100 employees, but by 1987, workdays lost due to obesity exceeded that attributable to smoking. In 2007, workdays lost from obesity were 3.7 times higher than for smoking.

CONCLUSIONS

Owing to the increasing trend in obesity, the productivity impact on employers from obesity will continue to rise without effective measures supporting employee efforts to achieve healthy weight through sustainable lifestyle changes.

Cancer mortality in workers exposed to dieldrin and aldrin: over 50 years of follow up

OBJECTIVE

Dieldrin and aldrin, pesticides widely used until the 1970s, have been under suspicion of being carcinogenic. In this study, overall and cause-specific mortality was assessed in a cohort of 570 employees occupationally exposed to the pesticides dieldrin and aldrin to investigate the long-term health effects, in particular carcinogenic effects.

METHODS

All of the employees worked in the production plants between January 1954 and January 1970 and were followed for cause-specific mortality until 30 April 2006. Based on dieldrin levels in blood samples taken from 343 workers during the exposure period, the total intake of dieldrin was estimated for each individual subjects in the cohort. The estimated total intake ranged from 11 to 7,755 mg of dieldrin, with an average of 737 mg.

RESULTS

Two hundred and twenty-six workers had died before 30 April 2006 compared with an expected number of 327.3, giving a standardized mortality ratio (SMR) of 69.0 (95% confidence interval (CI): 60.3-78.7). Overall cancer mortality was also significantly lower than expected (SMR: 76.4, 95% CI: 60.8-94.9). Also, none of the specific cancer sites showed a significant excess mortality and no association between exposure level and cancer mortality was found.

CONCLUSION

The results from this study support findings from other epidemiological and recent animal studies concluding that dieldrin and aldrin are not likely human carcinogens.

The Impact of Obesity on Illness Absence and Productivity in an Industrial Population of Petrochemical Workers

PURPOSE

Examine employee illness absence and the economic impact of overweight and obesity in a petrochemical industry workforce.

METHODS

A 10-year follow-up (1994-2003) of 4153 Shell Oil Company employees was conducted. Absence frequency rates and average number of workdays lost were calculated for normal weight, overweight, and obese employees with and without the presence of additional risk factors. The study also assessed the change in overweight and obesity prevalence in the study population and estimated the current and future economic impact of these conditions.

RESULTS

Overall, obese employees were 80% more likely to have absences (24.0 vs. 13.3 per 100 employees) and were absent 3.7 more days (7.7 vs. 4.0 days) per year compared with those employees with normal body weights. Among employees with no additional risk factors, overweight employees lost more than 1.5 times more days (4.2 vs. 2.6 days) per year, and obese employees more than 2.5 times more days (7.2 vs. 2.6 days) compared with their normal-weight colleagues. Similarly, absence frequency attributable to cardiovascular disease significantly increased among employees with one or two additional risk factors present, such as smoking, high blood pressure, or hypercholesterolemia. The direct cost of illness absence from overweight and obesity for this study population was $1,873,500. Furthermore, 31% of the total illness absence was attributable to overweight and obesity in 1994, and the percentage had risen to 36% by 2003.

CONCLUSIONS

The economic impact to employers is great and will continue to rise unless measures are taken, particularly to reduce the number of employees moving from overweight to obesity with time.

A 56-year mortality follow-up of Texas petroleum refinery and chemical employees, 1948-2003

OBJECTIVE

To further investigate the mortality risk of employees who worked in the petroleum refinery industry, we updated an earlier investigation by extending the mortality follow-up by an additional 14 years through 2003.

METHODS

The cohort consisted of 10,621 employees with an average follow-up of 34 years. We used the standardized mortality ratio (SMR) adjusted for age, race, and calendar years as a measure of risk.

RESULTS

Overall mortality (SMR=0.77, 95% confidence interval [CI], 0.74-0.79), all cancer mortality (SMR=0.87, 95% CI=0.82-0.93), and most cause-specific mortalities for the total study population were lower than or similar to that of the population of Harris County, Texas. This study did not show a significant increase in leukemia in the total population or in any of the subgroups. The only statistically significant excess of mortality found in this study was an increase in mesothelioma among maintenance employees; the SMR was 4.78 (95% CI=2.54-8.17) among employees who worked for a minimum of one year and was 7.51 (95% CI=3.75-13.45) among those with 10 or more years of employment and 20 or more years of latency.

CONCLUSIONS

After more than half a century of follow-up, employees at this facility continue to show more favorable mortality outcomes than the general local population. Overall, no statistically significant increase of leukemia or of any of the specific cell types was found. The increased mesothelioma is likely related to past exposure to asbestos.

Impact of a disability management program on employee productivity in a petrochemical company

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.

Exploring the relationships between diabetes and smoking: with the development of glucose equivalent concept for diabetes management

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.

Paradoxical increase in cigarette smuggling after the market opening in Taiwan

OBJECTIVES

To assess the magnitude of cigarette smuggling after the market opened in Taiwan.

METHODS

Review of tobacco industry documents for references to smuggling activities related to Taiwan and government statistics on seizure of smuggled cigarettes.

RESULTS

The market opening in 1987 led to an increase in smuggling. Contraband cigarettes became as available as legal ones, with only a small fraction (8%) being seized. Being specifically excluded from the market-opening, Japan entered the Taiwan market by setting up a Swiss plant as a legal cover for smuggling 10-20 times its legal quota of exports to Taiwan. Smuggling in Taiwan contributed to increased consumption of foreign brands, particularly by the young. Taiwan, not a member of the World Health Organization, was excluded from the East Asian 16-member "Project Crocodile", a regional anti-smuggling collaborative effort to implement the Framework Convention on Tobacco Control.

CONCLUSIONS

Taiwan showed a sharp increase in smuggling after market liberalisation. Being excluded from the international community, Taiwan faces an uphill battle to fight smuggling alone. If Taiwan remained as its weakest link, global efforts to reduce tobacco use will be undermined, particularly for countries in the East Asian region.

Obesity and mortality in a prospective study of a middle-aged industrial population

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.

Age at retirement and long term survival of an industrial population: prospective cohort study

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.

A hematology surveillance study of petrochemical workers exposed to 1,3 butadiene

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.

Illness Absence Patterns Among Employees in a Petrochemical Facility: Impact of Selected Health Risk Factors

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.

The impact of the cigarette market opening in Taiwan

OBJECTIVE

To assess the effect of the opening of the Taiwanese cigarette market on cigarette consumption, changes in market share, and the effects on tobacco control efforts.

METHODS

With the use of key word "Taiwan", the Legacy Tobacco Documents Library of the University of California, San Francisco, was searched for internal documents related to smuggling activities, promotion of light cigarettes, and market share analyses in Taiwan. Age adjusted smoking rates and cigarette and betel quid consumption before and after market opening were compared.

RESULTS

By 2000, the market share of imported cigarettes increased from less than 2% in 1986 to nearly 50%, and per capita cigarette consumption increased 15% following market opening. Because of the sharp increase in smuggling, with contraband cigarettes being as popular as legal imports, and the rapid proliferation of retail outlets, such as betel quid stalls, the market penetration by foreign tobacco companies was greater in Taiwan than among the other Super 301 Asian countries. Aggressive cigarette marketing strategies were associated with a 6% increase in adult male smoking prevalence, and with a 13% increase in the youth rate, within three years after market opening. The market opening also had an incidental effect on increasing the popularity of betel quid. Betel quid chewing has since become a major public health problem in Taiwan.

CONCLUSION

The opening of the cigarette market in 1987 had a long lasting impact on Taiwan. It increased smoking prevalence and the market has become dominated by foreign companies. The seriousness of smuggling and its associated loss of revenue by the government, the extent of increased youth smoking and its associated future health care costs, and the increased use of betel quid and the associated doubling of oral cancer mortality rates each pose significant problems to Taiwan. However, the market opening galvanised anti-smoking sentiment and forced the government to initiate and intensify a series of tobacco control efforts.

Excess injury mortality among smokers: a neglected tobacco hazard

OBJECTIVE

To assess the mortality risks from injuries for smokers and ex-smokers and to quantify the mortality burden of smoking from injury in Taiwan.

METHODS

Smokers' (and ex-smokers') mortality risks from injuries were compared with that of non-smokers in a merged cohort from Taiwan. A total of 64,319 male subjects were followed up for 12-18 years. Relative risks (RR) (adjusted for age and alcohol use) and 95% confidence intervals (CI) for cause specific injury deaths were calculated using the Cox proportional hazard model. Relative risks of injury mortality were also calculated to assess the presence of dose-response relations with daily smoking quantity.

RESULTS

Alcohol use adjusted relative mortality risks for all injuries (RR 1.69, 95% CI 1.39 to 2.05) including those from motor vehicle accidents (RR 1.88, 95% CI 1.44 to 2.45) and non-motor vehicle accidents (RR 1.48, 95% CI 1.11 to 1.99) were significantly higher for smokers than non-smokers. Mortality was also increased for most subtypes of non-motor vehicle injuries including falls, fires, and job related injuries. Furthermore, these increases were dose dependent, with the heaviest smokers having the highest risk and the lightest smokers the lowest risk, and ex-smokers, no increase. In 2001, over one fifth (23%) of all male injury deaths in Taiwan was associated with smoking.

CONCLUSION

This study demonstrated the significant association between fatal injuries and smoking. This relation adds further weight to smoking cessation campaigns.

Workplace smoking related absenteeism and productivity costs in Taiwan

OBJECTIVE

To estimate productivity losses and financial costs to employers caused by cigarette smoking in the Taiwan workplace.

METHODS

The human capital approach was used to calculate lost productivity. Assuming the value of lost productivity was equal to the wage/salary rate and basing the calculations on smoking rate in the workforce, average days of absenteeism, average wage/salary rate, and increased risk and absenteeism among smokers obtained from earlier research, costs due to smoker absenteeism were estimated. Financial losses caused by passive smoking, smoking breaks, and occupational injuries were calculated.

RESULTS

Using a conservative estimate of excess absenteeism from work, male smokers took off an average of 4.36 sick days and male non-smokers took off an average of 3.30 sick days. Female smokers took off an average of 4.96 sick days and non-smoking females took off an average of 3.75 sick days. Excess absenteeism caused by employee smoking was estimated to cost USD 178 million per annum for males and USD 6 million for females at a total cost of USD 184 million per annum. The time men and women spent taking smoking breaks amounted to nine days per year and six days per year, respectively, resulting in reduced output productivity losses of USD 733 million. Increased sick leave costs due to passive smoking were approximately USD 81 million. Potential costs incurred from occupational injuries among smoking employees were estimated to be USD 34 million.

CONCLUSIONS

Financial costs caused by increased absenteeism and reduced productivity from employees who smoke are significant in Taiwan. Based on conservative estimates, total costs attributed to smoking in the workforce were approximately USD 1032 million.

Smoking attributable mortality for Taiwan and its projection to 2020 under different smoking scenarios

OBJECTIVES

To estimate smoking attributable mortality (SAM) in Taiwan for the years 2001 through 2020 under scenarios of reductions in smoking rates by 0%, 2%, 4%, and 10% per year.

METHOD

The smoking attributable fraction (SAF) was used to calculate SAM from the risk experience in following up a large cohort (86 580 people) in Taiwan. Smoking rates were based on the 2001 National Health Interview Survey and other national surveys. An average 10 year lag was assumed between smoking rates and subsequent mortality.

RESULTS

In 2001, 18 803 deaths, or 1 out of 4 deaths (27%), in middle aged men (35-69 years old) were attributable to smoking. SAM has been increasing and will continue to increase if smoking rates remain constant or even if reduced annually by 2%. SAM would begin to decrease only if rates were to be reduced by at least 4% a year.

CONCLUSIONS

The projected SAM in this study illustrates the seriousness of smoking caused mortality. Current efforts in tobacco control would lead to a progressive increase in SAM, unless efforts were doubled and smoking rates reduced by more than 4% a year. The urgency in requiring stronger tobacco control programmes to attenuate the staggering death tolls is compelling.

Reducing health disparity in Taiwan: quantifying the role of smoking

OBJECTIVE

To assess the impact of smoking disparities on health disparities, in terms of gap in life expectancy, in Taiwan cities and counties.

METHODS

Using the decomposition method of life expectancy, the contribution of each disease category to the life expectancy gap was quantitatively expressed as the number of years of life. The smoking attributable fraction (SAF) was calculated for each city and county based on their respective smoking prevalence and relative risk for each smoking related disease. The smoking attributable gap (SAG) in life expectancy between two sites is the sum of the difference in SAF between two sites for each smoking related disease multiplied by the number of years this disease contributed to the life expectancy gap.

RESULTS

Significant health and smoking disparities were present among the 23 cities and counties in Taiwan. These health disparities and smoking disparities were highly correlated (R2 = 0.3676). Generally, the health gap increased with increasing smoking disparity. The disparity in smoking prevalence and intensity among cities and counties in Taiwan was responsible for up to 19% of the health disparity. The health disparity is also highly correlated (R2 = 0.3745) with SAG in life expectancy.

CONCLUSIONS

Reducing smoking is important to health, and reducing the smoking disparity is also important for reducing the health disparity observed in Taiwan. The larger the health disparity is, the more important the smoking attributable disparity could be. The reduction of smoking disparities could be a realistic and cost effective way toward reducing health disparities.

Role of parents and peers in influencing the smoking status of high school students in Taiwan

OBJECTIVES

To assess parental influence on smoking behaviour by high school students in an Asian culture and to compare the relative importance of parental and peer influence.

METHODS

A 5% nationally representative sample, including 44 976 high school students in 10th to 12th grade (aged 15-18 years) in Taiwan, were surveyed in 1995. Each completed a long self administered questionnaire. Parental influence was measured by examining both parental behaviour (smoking status) and attitudes (perceived "tender loving care" (TLC) by adolescents). Changes in smoking status were used to determine peer influence, defined as the increase in the likelihood of smoking from grade 10 to 12 in a steady state environment. Odds ratios (ORs) were calculated for parental and peer influence, using logistic regression.

RESULTS

Adolescents of smoking parents with low TLC had the highest smoking rates and those of non-smoking parents with high TLC had the lowest. The difference was more than twofold in boys and more than fourfold in girls. When either parental smoking status or TLC alone was considered, parental influence was similar to peer influence in boys, but larger than peer influence in girls. However, when smoking status and TLC were considered jointly, it became larger than peer influence for both groups (OR 2.8 v 1.8 for boys and OR 3.9 v 1.3 for girls).

CONCLUSION

When parental influence is taken as parental behaviour and attitude together, it plays a more important role than peer influence in smoking among high school students in Taiwan. This study, characterising such relationships among Asian populations for the first time, implies that future prevention programmes should direct more efforts toward the parental smoking and parent-child relationships, and not aim exclusively at adolescents in schools.

Are marketing campaigns in Taiwan by foreign tobacco companies targeting young smokers?

OBJECTIVE

To assess the impact of promotions on cigarette sales in Taiwan after the cigarette market opened to foreign companies, and to assess whether young smokers were targeted by these companies.

METHODS

Trends in cigarette sales, advertising expenditure, brand preference, and cigarette consumption were examined for the period following the 1987 opening of the cigarette market. Tobacco industry internal documents from Legacy Tobacco Documents Library of the University of California, San Francisco, were searched for corporate strategies on promoting youth consumption in Taiwan.

RESULTS

Between 1995 and 2000, the inflation adjusted advertising expenditures by all foreign firms increased fourfold. Much of the expenditure was spent on brand stretching the Mild Seven (Japan) and Davidoff (Germany) brands in television advertising. By 2000, the market share of foreign cigarettes exceeded domestics by three to one among young smokers and the leading brand preferred by this segment shifted from the most popular domestic brand (Long Life) to a foreign brand (Mild Seven). Furthermore, there was a sudden increase of 16.4% in smoking rates among young adults (from 36.1% to 42.0%) during the first five years after the market opened. This was also accompanied by increased per capita cigarette consumption and decreased age of smoking initiation. Industry documents confirmed the use of strategies targeted at the young. In particular, establishing new point of sale (POS) retail stores or promotional activities at POS were found to be more effective than advertising in magazines.

CONCLUSIONS

This study provides evidence that advertising increased with increased competition following the market opening, which, in turn, spurred cigarette sales and consumption. Foreign tobacco companies have deliberately targeted youth in Taiwan and succeeded in gaining three quarters of their cigarette purchases within a decade. Expanding youth consumption will incur excessive future health care costs borne by society. Foreign tobacco companies should be obligated to reimburse these expenses through higher tariffs on cigarettes.

Uncovering the relation between betel quid chewing and cigarette smoking in Taiwan

OBJECTIVE

To describe the characteristics of betel quid chewers and to investigate the behavioural and mortality relations between betel quid chewing and cigarette smoking.

METHOD

Prevalence and mortality risks of betel quid chewers by smoking status were calculated, based on the National Health Interview Survey in 2001 and a community based cohort, respectively. Cox's proportional hazards model was used to adjust mortality risks for age, alcohol use, and education.

RESULTS

Almost all betel quid chewers were smokers, and most started chewing after smoking. Chewers were predominantly male, mostly in their 30s and 40s, more likely being among the lowest educational or income group, and residing in the eastern regions of Taiwan. On average, betel quid chewers who smoked consumed 18 pieces of betel quid a day, and smoked more cigarettes per day. Far more smokers use betel quid than non-smokers (27.5% v 2.5%), but ex-smokers quit betel quid more than smokers (15.1% v 6.8%). The significantly increased mortality of betel quid users who also smoked, for all causes, all cancer, oral cancer, and cancer of the nasopharynx, lung, and liver, was the result of the combined effects of chewing and smoking. Smokers who chewed betel quid nearly tripled their oral cancer risks from a relative risk of 2.1 to 5.9. Increasing the number of cigarettes smoked among betel quid chewers was associated with a synergistic effect, reflective of the significant interaction between the two.

CONCLUSION

To a large extent, the serious health consequences suffered by betel quid chewers were the result of the combined effects of smoking and chewing. Betel quid chewing should not be considered as an isolated issue, but should be viewed conjointly with cigarette smoking. Reducing cigarette smoking serves as an important first step in reducing betel quid chewing, and incorporating betel quid control into tobacco control may provide a new paradigm to attenuate the explosive increase in betel quid use in Taiwan.

The health benefits of smoking cessation for adult smokers and for pregnant women in Taiwan

OBJECTIVE

To assess the benefits of smoking cessation regarding mortality reduction after smokers quit, and regarding the health of newborns after smoking mothers quit.

METHODS

Relative mortality risks (RR) for smokers aged 35 or older who quit years ago were calculated from the follow up of 71 361 civil servants and teachers recruited since 1989. Data from the Pregnancy Risk Assessment Monitoring System in Taipei City were used to calculate the odds ratios of body weights of newborns born to mothers of different smoking status.

RESULTS

Mortality risk for ex-smokers was significantly lower than that of current smokers for all causes (18%), all cancer (22%), lung cancer (39%), and ischaemic heart disease (54%). These benefits were not distinguishable initially, up to five years, but by year 17 and thereafter, substantial benefits of cessation accrued. Two thirds of smoking women quit during the first trimester of pregnancy, and only 2.2% of mothers smoked throughout pregnancy. The newborns from smoking mothers were smaller than those from never smoking mothers, but, if these mothers quit early in the first trimester, birth weights were normal.

CONCLUSIONS

The health benefits of smoking cessation, rarely reported for Asian populations, have been largely ignored by smokers in Taiwan, where cessation activities have been extremely limited. Findings of this study that risks from smoking can be attenuated or reversed should be widely communicated to motivate smokers to quit. Smokers should quit early, including smoking mothers, and not wait till medical conditions surfaced, to have the maximal benefits of cessation.

Smoking behaviour in Taiwan, 2001

PURPOSE

To examine smoking behaviours in Taiwan and compare those behaviours to those in the USA.

METHODS

Using the National Health Interview Survey (NHIS) of Taiwan (2001), a survey of over 20 000 participants, frequencies were calculated for smoking, ex-smoking, quantity smoked, and exposure to environmental tobacco smoke (ETS). Breakdowns by age, sex, and socioeconomic status were also calculated.

RESULTS

The ratio of male to female smoking rates was 10.9 to 1 among adults (46.8%/4.3%), but 3.6 to 1 among underage teenagers (14.3%/4.0%). The proportion of underage to adult smokers was three times higher for girls than for boys. Smoking prevalence substantially increased during and after high school years, and peaked in those aged 30-39 years. Smoking rates of high school age adolescents increased more than threefold if they did not attend school or if they finished their education after high school. Low income and less educated smokers smoked at nearly twice the rate of high income and better educated smokers. The smoker/ex-smoker ratio was close to 7. Male daily smokers smoked on average 17 cigarettes/day, and females, 11. Half of the total population, especially infants and women of childbearing age, were exposed to ETS at home.

CONCLUSIONS

Taiwan has particularly high male smoking prevalence and much lower female prevalence. The low female prevalence is likely to increase if the current sex ratio of smoking by underage youth continues. The low quit rate among males, the high ETS exposure of females and young children at home, and the sharp increase in smoking rates when students leave school, are of particular concern. These observations on smoking behaviour can provide valuable insights to assist policymakers and health educators in formulating strategies and allocating resources in tobacco control.

Workplace smoking policies in Taiwan and their association with employees' smoking behaviours

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.

Controlling cigarette smoking in the workplace in Taiwan: opportunities and challenges

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.

Effects of flux enhancing polymer on the characteristics of sludge in membrane bioreactor process

A newly developed membrane performance enhancer (MPE) was used to prevent membrane fouling in a membrane bioreactor (MBR) process. It transpired that 1,000 mg/l of MPE reduced polysaccharide levels from 41 mg/I to 21 mg/I on average under the experimental condition. Repeated experiments also confirmed that 50-1,000 mg/l of MPE could reduce membrane fouling significantly and increase the intervals between membrane cleanings. Depending on MPE dosages and experimental conditions, trans-membrane pressure (TMP) increase was suppressed for 20-30 days, while baseline TMP surged within a few days. In addition, MPE allowed MBR operation even at 50,000 mg/l of total solid and reduced permeate COD. However, no evidence of toxicity for sludge was found from respiratory works.

A hematology surveillance study of petrochemical workers exposed to benzene

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.

Cancer incidence among refinery and petrochemical employees in Louisiana, 1983–1999

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.

Mortality patterns among residents in Louisiana's industrial corridor, USA, 1970-99

BACKGROUND

Because of the high concentration of oil refining and petrochemical facilities, the industrial area of the lower Mississippi River of South Louisiana has been termed the Industrial Corridor and has frequently been referred to as the "Cancer Corridor".

AIMS

To quantitatively assess the "Cancer Corridor" controversy based on mortality data available in the public domain, and to identify potential contributing factors to the observed differences in mortality.

METHODS

Age adjusted mortality rates were calculated for white and non-white males and females in the Industrial Corridor, Louisiana, and the United States for the time periods 1970-79, 1980-89, and 1990-99.

RESULTS

All-cause mortality and all cancer combined for white males in the Industrial Corridor were significantly lower than the corresponding Louisiana population while Louisiana had significantly higher rates than the US population for all three time periods. Cancer of the lung was consistently higher in the Industrial Corridor region relative to national rates but lower than or similar to Louisiana. Non-respiratory disease and cerebrovascular disease mortality for white males in the Industrial Corridor were consistently lower than either Louisiana or the USA. However, mortality due to diabetes and heart disease, particularly during the 1990s, was significantly higher in the Industrial Corridor and Louisiana when compared to the USA. Similar mortality patterns were observed for white females. The mortality for non-white males and females in the Industrial Corridor was generally similar to the corresponding populations in Louisiana. There were no consistent patterns for all cancer mortality combined. Stomach cancer was increased among non-whites in both the Industrial Corridor and Louisiana when compared to the corresponding US data. Mortality from diabetes and heart disease among non-whites was significantly higher in the Industrial Corridor and Louisiana than in the USA.

CONCLUSIONS

Mortality rates in the Industrial Corridor area were generally similar to or lower than the State of Louisiana, which were increased compared to the United States. Contrary to prior public perceptions, mortality due to cancer in the Industrial Corridor does not exceed that for the State of Louisiana.

Bridging the gap in life expectancy of the aborigines in Taiwan

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.

A mortality and morbidity study of refinery and petrochemical employees in Louisiana

AIMS

To examine the mortality experience of 4221 employees from 1973 to 1999 and the illness absence patterns for 2203 employees from 1990 to 1999 of a chemical and refinery facility in Louisiana.

METHODS

Mortality and illness absence data were extracted from the Shell Oil Company's health surveillance system (HSS). The standardised mortality ratio was used as a measure of mortality risk. Morbidity frequency and duration of absence were calculated by age, sex, and four health risk factors (cigarette smoking, high blood pressure, hypercholesterolaemia, and obesity).

RESULTS

Male employees experienced a significant deficit in mortality for all causes of death, all cancers, lung cancer, heart disease, and respiratory disease compared with the corresponding US population. Brain cancer was non-significantly increased, with six observed and five expected deaths; mortality from leukaemia was consistently lower than expected. The majority of employees had no illness absences of six days or longer during the 10 year study period. The loss of productivity (in terms of days of absence) was greater for employees with health risk factors. Ever smoking male employees had a 79% increase of heart disease and more than 50% higher rates of respiratory disease and musculoskeletal disorders compared to non-smokers. Smokers were absent 2.9 and 1.6 more days than non-smokers and ex-smokers, respectively.

CONCLUSIONS

Regardless of the comparison population, significantly fewer deaths were seen for all causes combined, all cancers, lung cancer, heart disease, or non-malignant respiratory disease. Illness absence rates and duration were higher among employees with health risk factors.

Ten years' experience using an integrated workers' compensation management system to control workers' compensation costs

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.

Asbestos related diseases from environmental exposure to crocidolite in Da-yao, China. I. Review of exposure and epidemiological data

BACKGROUND

Scattered patches of crocidolite, one form of asbestos, were found in the surface soil in the rural county of Da-yao in southwestern China. In 1983, researchers from the West China University of Medical Sciences (WCUMS) discovered that residents of two villages in Da-yao had hyperendemic pleural plaques and excessive numbers of pleural mesotheliomas.

AIMS

To review and summarise epidemiological studies, along with other relevant data, and to discuss the potential contribution to environmental risk assessment.

METHODS

This report is based on a review of several clinical/epidemiological studies conducted by WCUMS researchers since 1984, which included one cross sectional medical examination survey, one clinical/pathological analysis of 46 cases of mesothelioma, and three retrospective cohort mortality studies. Additional information acquired from reviewing original data first hand during a personal visit along with an interview of medical specialists from Da-yao County Hospital was also incorporated.

RESULTS

The prevalence of pleural plaque was 20% among peasants in Da-yao over 40 years of age in the cross sectional survey. The average number of mesothelioma cases was 6.6 per year in the 1984-95 period and 22 per year in the 1996-99 period, in a population of 68 000. For those mesothelioma cases that were histology confirmed, there were 3.8 cases/year in the first period and 9 cases/year in the second. Of the 2175 peasants in this survey, 16 had asbestosis. Lung cancer deaths were significantly increased in all three cohort studies. The annual mortality rate for mesothelioma was 85 per million, 178 per million, and 365 per million for the three cohort studies, respectively. The higher exposed peasants had a fivefold increased mesothelioma mortality compared to their lower exposed counterparts. There were no cases of mesothelioma in the comparison groups where no crocidolite was known to exist in the environment. In the third cohort study, almost one of five cancer deaths (22%) was from mesothelioma. The ratio of lung cancer to mesothelioma deaths was low for all three studies (1.3, 3.0, and 1.2, respectively).

CONCLUSIONS

The observation of numerous mesothelioma cases at Da-yao was a unique finding, due mainly to their lifetime exposure to crocidolite asbestos. The finding of cases dying at a younger age and the relatively high ratio of mesothelioma cases to lung cancer could also be another unique result of lifetime environmental exposure to crocidolite asbestos. Although the commercial use of crocidolite has been officially banned since 1984, the incidence of mesothelioma has continued to show a steady increase, particularly among peasants. Since the latency of mesothelioma is approximately 30-40 years, the ban had little effect in the 1990s. The increased awareness and changes in diagnosis over time may also contribute to the increase. Furthermore, exposure to asbestos stoves and walls continued. The government implemented reduction of these exposures. However, from a public health standpoint, the most important issue is the complete avoidance of further exposure to asbestos.

Health findings from a mortality and morbidity surveillance of refinery employees

PURPOSE

To present results from a prospective mortality (1973-1998) and morbidity (1990-1998) surveillance of a refinery population in California.

METHODS

Mortality and illness-absence data were extracted from the Shell Oil Company's Health Surveillance System (HSS). Mortality data were compared to the United States, the state of California, and Contra Costa County, where the refinery is located. Morbidity data were compared to other company manufacturing employees. The standardized mortality/morbidity ratio (SMR/SMbR) was used as a measure of risk. Morbidity frequency and duration of absence were calculated by age, sex, and four health risk factors (smoking, high blood pressure, hypercholesterolemia, and obesity).

RESULTS

With the United States as a comparison, the all causes combined SMR was 0.84 [95% confidence interval (CI) = 0.78-0.90], and the SMR for all cancer was 0.75 (95% CI = 0.64-0.88). Statistically significant deficits in mortality were found for lung cancer (SMR = 0.60) and leukemia (SMR = 0.26). Morbidity frequency and duration of absence among smokers were substantially higher than those of nonsmokers. Similar results were also noted for obese employees when compared to those of normal weight.

CONCLUSIONS

Regardless of the comparison population, significantly fewer deaths were seen for all causes combined, all cancer, lung cancer, and leukemia. The study also showed no increased mortality from cancer of the stomach, kidney, skin, prostate, and brain. The increased morbidity frequency and duration of absence were associated with the presence of known health risk factors. These study findings are useful in setting priorities for medical programs and directing efforts such as health promotion and disease prevention strategies.

Trends in cigarette smoking among refinery and petrochemical plant employees with a discussion of the potential impact on lung cancer

OBJECTIVE

To examine trends in cigarette smoking prevalence and intensity among petroleum industry employees over a 22-year period, from 1976 to 1997, and to evaluate the hypothesis that the (about 20%) lower lung cancer mortality, when compared with the general population, among these workers is due to lower average cigarette consumption.

METHODS

Self-reported smoking prevalence and intensity (number of cigarettes smoked per day) data were available from the Shell Health Surveillance System for approximately 5,400 employees in the 1970s, 11,000 in the 1980s, and 8,300 in the 1990s. Data were analyzed by gender, time period, and work status (production vs. staff).

RESULTS

During the 22-year study period, smoking prevalence dropped significantly in this working population. When compared with the general US population, smoking prevalence trends were very similar. For the entire employee population, smoking prevalence was highest for women working in production (hourly) jobs. While smoking prevalence was higher among production employees than among staff employees, daily cigarette consumption was slightly lower. Cigarette consumption among Shell employees was similar to that in the US in the 1970s, but lower in the 1980s and 1990s. By applying smoking consumption data from the 1970s, the ratio of weighted lung cancer relative risks for Shell employees and the US general population was 0.98. In other words, the lung cancer mortality rate of refinery and petrochemical employees would be adjusted upward by 2% if one were to remove the influence of smoking consumption by Shell employees.

CONCLUSIONS

Based on our data, it is unlikely that differences in smoking prevalence and intensity between refinery/petrochemical workers and the general population could account for the lower risk of lung cancer mortality reported in the literature.

A mortality, morbidity, and hematology study of petrochemical employees potentially exposed to 1,3-butadiene monomer

This three-part study is an update of a previous report that examined the mortality, morbidity, and hematological data of employees from a petrochemical facility in Texas who had potential exposure to 1,3-butadiene monomer. The first part describes the updated cause-specific mortality of 614 workers. Vital status for each cohort member was ascertained through 1998, a 9-year extension of the previous study. The second part is an examination of the morbidity experience of cohort members who were still working during 1992-1998, including 289 of the 614 mortality cohort members. The third part is an evaluation of the hematological results from routine health surveillance and/or medical examinations. Approximately 430 of the 614 employees who had complete blood count (CBC) data as of December 1999 were included in the hematological evaluations. The most recent examination containing CBC data was used and compared with similar data for over 2600 other employees from this facility. Overall mortality during the follow-up period, 1948-1998, was significantly lower than for the local comparison population (standardized mortality ratio (SMR) of 0.55 with a 95% confidence interval (CI) of 0.42-0.70). Mortality for all cancer was also significantly lower (SMR, 0.57; 95% CI, 0.32-0.92). Mortality for all lymphohematopoietic cancer was about the same as the comparison population (SMR, 1.06; 95% CI, 0.22-3.11). None of the cause-specific morbidity was in excess compared with an internal comparison group. There were no differences in the distribution or mean values of hematological variables (e.g. white blood cells, red blood cells, hemoglobin, platelets, mean corpuscular volume) between the butadiene cohort and the comparison group, or between a subgroup of workers in jobs with the highest potential for butadiene exposure (i.e. shipping) and the rest of the butadiene cohort. The findings of this study suggest that the butadiene exposure at this facility in the last 20 years does not pose a health hazard to employees.

Characterization of novel neutralizing monoclonal antibodies specific to human neurturin

Neurturin (NTN) a structural and functional relative of glial cell line-derived neurotrophic factor, was originally identified based on its ability to support the survival of sympathetic neurons in culture. Similar to glial cell line-derived neurotrophic factor (GDNF), Neurturin has been shown to bind to a high affinity glycosylphosphatidylinositol (GPI)-linked receptor (GFRalpha2) and induce phosphorylation of the tyrosine kinase receptor Ret, resulting in the activation of the mitogen activated protein kinase (MAPK) signalling pathway. A panel of six novel murine monoclonal antibodies (MAbs) specific to human Neurturin has been developed and characterized. Four of the MAbs tested inhibit, to varying degrees, binding of NTN to the GPI-linked GFRalpha2 receptor. Three MAbs cross-react with the murine homolog. These antibodies have been shown to be useful reagents for Western blotting, immunohistochemistry, and also for the development of a sensitive, quantitative enzyme-linked immunosorbent assay (ELISA) for human NTN. Novel, specific MAbs with varying epitope specificities and blocking activity will be valuable tools for both the in vitro and in vivo characterization of NTN and its relationship to the GFRalpha2 and Ret receptors.

An ergonomics program designed to reduce the incidence of upper extremity work related musculoskeletal disorders

In 1992, the Johns Hopkins Hospital and University initiated a program aimed at the early diagnosis and treatment of potential upper extremity work related musculoskeletal disorders (UEWMSDs), ergonomic assessment and abatement of work areas where individuals with UEWMSDs are employed, as well as the identification and correction of areas throughout the hospital and university where UEWMSDs could possibly occur. The program resulted in an initial increase in the number and cost for the treatment of UEWMSDs. Subsequently, there was a significant decrease in the number of UEWMSDs reported and virtual elimination of the need to use surgical procedures to correct these conditions. This article suggests that a coordinated program of medical care, ergonomic assessment, and intervention can be efficacious in the primary, secondary, and tertiary prevention of UEWMSD.

Characterization and cloning of avian-hepatic glutathione S-transferases

Cytosolic glutathione S-transferases (GSTs) were isolated from 1-day-old Leghorn chick livers by glutathione (GSH)-affinity chromatography. After sample loading and extensive washing with 0.2 M NaCl, the column was sequentially eluted with 5 mM GSH and 1 mM S-hexylglutathione. The isolated GSTs were subjected to reverse-phase HPLC, electrospray ionization-MS, N-terminal and internal peptide sequencing analyses. The proteins recovered from the 5 mM GSH eluant were predominantly cGSTM1. A protein (cGSTM1') with an N-terminal amino acid sequence identical to that of cGSTM1 but with the initiator methionine retained and a novel class-mu isozyme (cGSTM2*) were also recovered from this fraction. Nine class-alpha isozymes with distinctive molecular masses were identified from the 1 mM S-hexylglutathione eluant. Three of these proteins are probably variants with minor amino acid substitutions of other isozymes. Of the six remaining class-alpha isozymes, three of them have had their complete (cGSTA1 and cGSTA2) or partial (cGSTA3) cDNA sequences reported previously in the literature. A chicken liver cDNA library was screened with oligonucleotides generated from the cGSTA2 sequence as probes. Clones that encompass the complete coding regions of cGSTA3 and cGSTA4 were obtained. A clone encoding the C-terminal 187 residues of cGSTA5 was also isolated.

Comparison of subcutaneous hydromorphone with intramuscular meperidine for immediate postoperative analgesia

Intramuscular (i.m.) injection with meperidine is the most common analgesic approach to treat postoperative pain in Taiwan. Hydromorphone (Dilaudid) can provide very potent and rapid analgesic effect through subcutaneous (s.c.) injection. Although hydromorphone is widely used in North America, no study has compared the analgesic efficacy, side effect profiles and patients' satisfaction with the method of injection of hydromorphone s.c. and meperidine i.m. for the immediate post-operative analgesia. In this randomized and double-blind study, 60 female patients scheduled for abdominal total hysterectomy were treated either with 1 mg hydromorphone s.c. (n = 30) or 50 mg meperidine i.m. (n = 30) when they regained consciousness and asked for analgesic treatment in the recovery room. Visual analogue score (VAS) of wound pain was obtained at 0, 10 and 30 min after injection by a blinded observer. The occurrence and severity of nausea, vomiting, dizziness, drowsiness, flatus passage and respiratory depression were recorded. Post-operative analgesia in the ward was maintained by patient-controlled analgesia (PCA) with intravenous morphine. Time to first PCA demand, the number of demands, delivery, delivery/demand ratio and 24 h morphine consumption were documented. We found that VAS was reduced at 10 min and, to a greater extent, at 30 min postinjection in both groups but with no significant difference between the two groups. The occurrence and severity of side effect profiles were similar in both groups except that dizziness was more frequently observed after meperidine injection. Delivery, demand, delivery/demand ratio and 24 hr morphine consumption by PCA were not significantly different between the two groups. Time to first PCA trigger was also similar. Patients receiving hydromorphone s.c. injection exhibited higher satisfactory score than those receiving meperidine i.m. injection. Hydromorphone 1 mg, injected subcutaneously, was as effective as intramuscular meperidine 50 mg while permitting more favorable injection technique and fewer side effects. We suggest that subcutaneous hydromorphone is a good alternative to intramuscular meperidine for postoperative analgesia in the recovery room.

Receptor binding and biological activity of mammalian expressed sensory and motor neuron-derived factor (SMDF)

Sensory and motor neuron-derived factor (SMDF) is a member of the neuregulin family of proteins. SMDF is structurally characterized by a novel N-terminal domain. Using the signal sequence and N-terminal 28 amino acids (the "epitope") of herpes simplex virus type 1 glycoprotein D (gD), we have expressed SMDF as an epitope-tagged protein (gD-SMDF) in 293 cells, and purified it to > 98% homogeneity on a monoclonal anti-gD column. gD-SMDF stimulates human Schwann cell growth and 3H-thymidine incorporation in MCF-7 and T47D human breast tumor cells in vitro. The biological activity of gD-SMDF is consistent with its ability to compete with 125I-labeled heregulinbeta1 peptide (rHRGbeta1(177-244)) to bind to soluble dimeric ErbB receptor-IgG fusion proteins. gD-SMDF binds with low affinity to homodimeric ErbB3-IgG and ErbB4-IgG but with higher affinity to heterodimeric ErbB2/ErbB3-IgG and ErbB2/ErbB4-IgG. Using a SMDF-IgG(Fc) fusion protein we generated a monoclonal antibody (3G11) which binds SMDF, crossreacts with rHRGbeta1(177-244), and neutralizes the in vitro activities of gD-SMDF and rHRGbeta1(177-244) in human Schwann cells.