Biomedical subjects

C E Ross

Publications and source records attributed to C E Ross.

At least 37 records · Page 2Linked to original sources

PubMed1996

Fundamental analysis in research on well-being: distress and the sense of control.

Fundamental analysis defines the basic terms of social and behavioral research. It usually follows the rule "one concept to a measure." However, some responses inherently reflect more than one underlying attribute, as when a test score reflects both knowledge of the subject and practice with taking tests. The standard methods of fundamental analysis break down in the presence of such cross-cutting factors. In this article, we discuss two instances of confusion and disagreement among social and behavioral scientists generated by the effects of cross-cutting factors on critical measures. In the first instance, a tendency to agree with the statements of others can make beliefs about personal control over events and outcomes seem unrelated to beliefs about control by chance, fate, or powerful others. The tendency to agree correlates positively with age. In the second instance, emotional expressiveness can make the frequency or intensity of sadness seem unrelated to the frequency or intensity of happiness. Women, who make up the large majority of older Americans, express themselves more freely than men. The apparent disjointedness of internal and external attributions of control, or of positive and negative emotions, results from methods assuming that the response to each question reflects one and only one underlying factor. Cross-cutting factor models eliminate the bias and confusion produced by response tendencies and help isolate and define the essential dimensions of response.

Aged↗

PubMed1996

Mortality study of employees with potential exposure to epichlorohydrin: a 10 year update.

OBJECTIVES: A 10 year extension of follow up (up to 1993) of 863 employees who had potential exposure to epichlorohydrin at two chemical plants between May 1948 and December 1965 was conducted to further evaluate the previously reported potential association between exposure to epichlorohydrin and heart disease. METHODS: The mortality observed was compared with that expected from the death rates from the local male population where these chemical plants are located. Workers were assigned to one of five exposure categories based on their job with the highest level of potential exposure. Vital status was ascertained to the end of 1993. RESULTS: Among diseases of particular interest, there were no excess deaths from heart disease (standardised mortality ratio (SMR) 63.3), lung cancer (SMR 63.8), or non-malignant respiratory disease (SMR 37.7) for employees with 20 or more years after first exposure. Based on the level of potential exposure to epichlorohydrin, mortality for heart disease was slightly higher (SMR 75.7, 95% confidence interval (95% CI) 51.8-106.7) in the moderate to heavy exposure group than in the none to light exposure group (SMR 59.5, 95% CI 37.7-89.3); this difference is well within the range of random variation. The SMR for heart disease was 90.4 among employees who had both probable exposure to allyl chloride and moderate to heavy exposure to epichlorohydrin, although it was 88.1 among employees who had moderate to heavy potential exposure to epichlorohydrin but no exposure to allyl chloride. CONCLUSIONS: This study does not support an association between exposure to epichlorohydrin and heart disease or lung cancer. There were no additional deaths from leukaemia in this update; the raised SMR for leukaemia noted in the previous study has substantially decreased from 500.0 to 161.3 (95% CI 33.2-471.0) and is not significant. The overall mortality and cancer mortality of employees potentially exposed to epichlorohydrin continued to be lower than that of the local population.

Adult↗

PubMed1996

A novel DNA repair response is induced in human cells exposed to ionizing radiation at the G1/S-phase border.

We have discovered a novel DNA repair response which is induced in cells irradiated with gamma rays at the G1/S-phase border. The induction of this repair response occurs at a stage in the cell cycle when overall levels of excision repair are reduced compared to cells irradiated in either S phase, G2/M phase or exponential growth. The induced repair is characterized by the formation of very long excision repair patches (VLERP) containing at least 150 nucleotides compared to the constitutive repair patches that are 3-5 nucleotides. These VLERP appear to be produced in response to a DNA lesion specific to ionizing radiation since they were not observed in cells irradiated with UV radiation at G1/S phase. The formation of VLERP requires both the nucleotide excision repair pathway, since they are absent in irradiated xeroderma pigmentosum group A cells, and the synthesis of new protein and mRNA. The time course for the induction of the VLERP shows an initial delay of 2 h, followed by a steady increase for up to 12 h after irradiation. By comparison, the production of the constitutive short repair patches shows an initial rapid production which levels out after 4 h.

Cells, Cultured↗

PubMed1996

Education, age, and the cumulative advantage in health.

The positive association between educational attainment and health is well established, but the way in which the education-based gap in health varies with age is not. Do the health advantages of high educational attainment and disadvantages of low educational attainment diverge or converge with age? The cumulative advantage perspective predicts a diverging SES gap in health with age, but past evidence does not allow us to accept or reject the hypothesis. We address this issue in two samples, cross-sectionally and over time, with three health measures. The first data set consists of a 1990 telephone interview of a national probability sample of U.S. households. There are 2,031 respondents, aged 18 to 90. The second is a national probability sample of U.S. households in which 2,436 respondents aged 20 to 64 were interviewed by telephone in 1979 and reinterviewed in 1980. We find that the gap in self-reported health, in physical functioning, and in physical well-being among people with high and low educational attainment increases with age. The health advantage of the well educated is larger in older age groups than in younger. Health advantages of high income and disadvantages of low income also diverge with age, but household income does not explain education's positive effect.

Activities of Daily Living↗

PubMed1995

Have sperm counts been reduced 50 percent in 50 years? A statistical model revisited.

OBJECTIVE: To reanalyze data that were used in a linear model to predict that mean sperm counts have been reduced globally by approximately 50% in the last 50 years. DESIGN: The mean sperm counts and their temporal distribution were reanalyzed via several different statistical models (quadratic, spline fit, and stairstep). CONCLUSION: There are several reasons why a published linear regression model is inappropriate to infer a 50% reduction in mean sperm counts in the last 50 years. These include [1] the potential selection biases that may have occurred with the 61 assembled studies such that they are not representative of their underlying populations; [2] the likely variability in collection methods, in particular, the lack of adherence to a minimum prescribed abstinence period, as has been stated for the largest study, which contained 29.7% of all the subjects included in the analysis; [3] the paucity of data in the first 30 years of the 50-year trend analysis; [4] the fact that if the last 20 years of data are examined, which contains 78.7% of all the studies and 88.1% of the total number of subjects, there is no decrease in sperm counts, in fact, sperm counts were observed to have increased; [5] the conflicting data from a large individual laboratory, which was not prone to the collection variability that likely occurred between the 61 studies, that did not suggest a decline in mean sperm count or seminal volume during a comparable time period, even though this laboratory published the data that were largely responsible for the high historical values in the linear model; and, most importantly, [6] the variety of other mathematical models that perform statistically better at describing the recent data than the linear model and thus offer substantially different hypotheses. The data are only robust during the last 20 years of the analysis, in which all the models, except the linear model, suggest constant or slightly increasing sperm counts.

Female↗

PubMed1995

Does employment affect health?

Employment correlates positively with health, but is employment cause or consequence? The social causation hypothesis says that employment improves the health of men and women. The selection hypothesis says that healthy people get and keep jobs more than unhealthy people do. We test both hypotheses using longitudinal data from a national probability sample (N = 2,436 interviewed in both years). In the equations representing social causation, full-time employment predicts slower declines in perceived health and in physical functioning for both men and women. Full-time employment has the same effect for both sexes. Among women, it also has the same effect for White and non-White, and for married and nonmarried. In the equations representing social selection, physical functioning increases the odds of getting or keeping a full-time job for both sexes. Perceived health increases the odds for women but not for men. In regard to homemaking among women, homemaking predicts significantly greater declines in health, but health has no effect on the odds of becoming or staying a homemaker.

Adult↗

PubMed1994

Mortality among employees at a plastics and resins research and development facility.

OBJECTIVES: The study was undertaken to update a previous study of employees from a resins and plastics research and development facility and to further examine the mortality of these employees with particular emphasis on deaths due to pancreatic cancer. METHODS: This retrospective cohort study examined mortality from 1962 to 1992 for 257 men who were employed for at least one year during a 14 year period from 1962 to 1975 at a plastics and resins research and development facility. During the operative period, the primary activities involved applications and process development for polypropylene, polystyrene, epoxy resins, and to a lesser extent high density polyethylene. RESULTS: The cohort was young and was followed up for an average of 26 years. Although mortality for all causes among employees who worked at least one year at this facility was low (standardised mortality ratio (SMR) 0.74), the death rate from cancer was moderately higher than that of the general population (14 observed and 9.4 expected deaths). There were four observed and 0.5 expected deaths from pancreatic cancer among men who worked at this facility for at least one year, which resulted in a statistically increased SMR of 8.88 (95% confidence interval 2.42-22.74). All cases of pancreatic cancer had "laboratory" jobs, and their ages at death were relatively young compared with deaths in the general population from pancreatic cancer. Lung cancer mortality was high but not significant with seven observed and 3.5 expected deaths. There were no deaths due to non-malignant respiratory disease (1.9 expected). CONCLUSIONS: The increased cancer mortality was entirely due to excess deaths from pancreatic and lung cancers. No causative agent or process for these cases of pancreatic cancer has been identified. This study shows no increased colorectal cancer mortality as was found among another group of workers involved in the manufacture of polypropylene.

Adult↗

PubMed1994

Mortality, morbidity, and haematological results from a cohort of long-term workers involved in 1,3-butadiene monomer production.

A retrospective mortality analysis and prospective morbidity and haematological analyses were performed for Shell Deer Park Manufacturing Complex (DPMC) male employees who worked in jobs with potential exposure to 1,3-butadiene from 1948 to 1989. 614 employees qualified for the mortality study (1948-89), 438 of those were still employed during the period of the morbidity study (1982-9), and 429 of those had haematological data available for analysis. Industrial hygiene data from 1979 to 1992 showed that most butadiene exposures did not exceed 10 ppm (eight-hour time weighted average (8 hour TWA)), and most were below 1 ppm, with an arithmetic mean of 3.5 ppm. 24 deaths occurred during the mortality study period. For all causes of death, the standardised mortality ratio (SMR) was 48 (95% confidence interval (95% CI) = 31-72), and the all cancer SMR was 34 (95% CI = 9-87). There were only two deaths due to lung cancer (SMR 42, 95% CI = 5-151) and none due to lymphohaematopoietic cancer (expected = 1.2). Morbidity (illness absence) events of six days or more for the 438 butadiene employees were compared with the rest of the complex. No cause of morbidity was in excess for this group; the all cause standardised morbidity ratio (SMbR) was 85 (95% CI = 77-93) and the all neoplasms SMbR was 51 (95% CI = 22-100). Haematological results for the 429 with laboratory data were compared with results for the rest of the complex. No significant differences occurred between the two groups and the distributions of results between butadiene and non-butadiene groups were virtually identical. These results suggest that butadiene exposures at concentrations common at DPMC in the past 10-20 years do not pose a health hazard to employees.

Adult↗

PubMed1994

Overweight and depression.

Is being overweight distressing? If it is, is the distress due to negative appraisals by others, to the stresses of trying to fit norms of thinness by dieting, or to the health consequences of being overweight? If being overweight is stigmatizing, negative evaluations by others may be internalized as high levels of depression. This perspective predicts that being overweight has a direct effect on depression, and that the effect is greater in social groups where being overweight is less common, especially among women, Whites, younger people, the well-educated, and the well-to-do. Alternatively, overweight may not be distressing per se. Instead, attempting to fit norms of appearance that equate thinness with attractiveness by dieting is distressing. According to this perspective, the association between being overweight and depression is explained by dieting. Finally, this association may be due to the health consequences of being overweight. A random sample of 2,020 U.S. adults aged 18-90 were interviewed by telephone in 1990. Results showed that being overweight has no direct effect on depression in any social group except among the well-educated. Overweight persons are more likely to diet and to experience worse physical health, both of which are associated with depression. Combined, these explain the negative effects of being overweight on depression.

Adolescent↗

PubMed1994

Sex stratification and health lifestyle: consequences for men's and women's perceived health.

A representative national sample of 2,031 adults aged 18 to 90 was interviewed by telephone in 1990. Results showed that men report better health than women, but that the gap closes with age. We argue that a gender difference in labor and lifestyles explains sex differences in perceived health across the life course: gender inequality in paid and unpaid work and the subjective experience of inequality disadvantage women, whereas lifestyle disadvantages men. Women are less likely to be employed, and are more likely to work part-time, have lower incomes and more economic hardship, and to do more unpaid domestic labor than men, all of which except domestic labor are associated with poor health. Domestic labor improves health, up to doing 60 percent of the housework. Women also have more distress and fewer subjective work rewards, both of which are associated with poor health. If women had the same levels of paid work, household income, economic hardship, work rewards, and distress as men, their health would equal that of men's and surpass it by age 59. Although we expected to find an overwhelming male disadvantage in lifestyle, we did not. Men are more likely than women to walk and to exercise strenuously, both of which are associated with good health. If women's labor and leisure-time physical activity equalled men's, women over the age of 54 would experience better health than men. Men's lifestyle disadvantage comes from their greater tendency to smoke and to be overweight, both of which are associated with poor health.

Adolescent↗

PubMed1993

A cohort mortality study of two California refinery and petrochemical plants.

This study examined the 1973 to 1989 mortality experience of Shell's two California manufacturing locations' employees who worked more than 6 months before December 31, 1989 and pensioners who were alive as of January 1, 1973. Vital status of each employee as of December 31, 1989 was determined from various sources including company records, the National Death Index, and the Social Security Administration's Master Beneficiary Record file. The study included many long-term employees, with more than half (57%) of the total population working 20 years or longer. The total population exhibited 11% lower all causes mortality and 20% lower cancer mortality, as compared with the California general population. There were no significant excesses of any cause-specific mortality including cancer. Among total employees, mortality for several cancer sites showed a statistically nonsignificant increase, for example, cancer of the kidney (8 observed deaths and 6.02 expected), cancer of the bladder (11 observed deaths and 9.17 expected), and Hodgkin's disease (2 observed deaths and 1.01 expected). A review of these work histories revealed no predominant work area or job assignment. In contrast to the ecologic studies based on local county rates, lung cancer mortality in this study was significantly lower (Standardized Mortality ratio [SMR] = 0.73). In addition, statistically significant deficits in mortality were found for cirrhosis of the liver (SMR = 0.63) and all external causes of death (SMR = 0.74). This study also failed to show an increased mortality rate for cancers of the brain, stomach, and prostate--causes which have been reported to be elevated in other refinery and petrochemical employee studies.

Adult↗

PubMed1992

A prospective study of morbidity patterns in a petroleum refinery and chemical plant.

This study examined the morbidity experience from 1981 to 1988 of a prospective cohort of 3422 refinery and petrochemical plant employees from the Shell Deer Park manufacturing complex. The morbidity data for this study, which include all illness and absence records in excess of five days, were extracted from the morbidity section of the Shell health surveillance system. Standardised morbidity ratios (SMRs) of disease prevalence in this cohort were calculated using an internal comparison group of all manufacturing employees of the Shell Oil Company. Among production employees, the overall morbidity was statistically significantly higher (SMR = 109) than that of the comparison group. Illness due to hypertension (SMR = 144), haemorrhoids (SMR = 149), diseases of the nervous system (SMR = 120), respiratory system (SMR = 108), and digestive system (SMR = 117) were also raised for this group. The increased risk due to these medical conditions does not appear to be associated with occupational factors. Lymphatic and haematopoietic tissue neoplasms were raised (SMR = 124), but were based on only four cases.

Acute Disease↗

PubMed1992

Age and depression.

In this study, the relationship between age and depression is analyzed, looking for effects of maturity, decline, life-cycle stage, survival, and historical trend. The data are from a 1990 sample of 2,031 U.S. adults and a 1985 sample of 809 Illinois adults. The results show that depression reaches its lowest level in the middle aged, at about age 45. The fall of depression in early adulthood and rise in late life mostly reflects life-cycle gains and losses in marriage, employment, and economic well-being. Depression reaches its highest level in adults 80 years old or older, because physical dysfunction and low personal control add to personal and status losses. Malaise from poor health does not create a spurious rise of measured depression in late adulthood. However, some of the differences among age groups in depression reflect higher education in younger generations, and some reflect different rates of survival across demographic groups that also vary in their levels of depression.

Activities of Daily Living↗

PubMed1992

Personal and job characteristics of musculoskeletal injuries in an industrial population.

A cross-sectional study was conducted of 10,350 full-time regular employees who worked at Shell Oil Company's manufacturing facilities between 1987 and 1989. Two hundred seventy-five employees with low-back and 456 with nonlow-back musculoskeletal injuries were compared with 8295 employees who did not have musculoskeletal injuries during this period. Based on morbidity data collected from a prospective health surveillance system, this study shows that estimated relative risks (RRs) for low-back injuries are significantly higher among smokers (RR = 1.54, P less than .01) and overweight persons (RR = 1.42, P less than .01). This observation is also true for nonlow-back musculoskeletal injury (RR = 1.23, P = .05 for smokers and RR = 1.53, P less than .01 for overweight persons). In addition, persons in potentially more physically demanding jobs (primarily maintenance job titles) had an increased RR for both low-back and nonlow-back musculoskeletal injuries (RR = 1.57, P less than .01 and RR = 1.35, P = .02, respectively). The findings of this study suggest that it may be possible to reduce the impact of musculoskeletal injury through implementation of an integrated injury prevention program. Such programs would include not only the traditional elements of job factors evaluation and modifications, employee education and training, and an overall increased attention to ergonomics but also medical counseling and support for personal fitness programs, workplace smoking cessation programs, and weight-reduction programs.

Accidents, Occupational↗

PubMed1991

Prospective morbidity surveillance of Shell refinery and petrochemical employees.

Results for a prospective morbidity study of 14,170 refinery and chemical workers from 1981 through 1988 are presented. Illness/absence data for this study were extracted from the morbidity section of the Shell Health Surveillance System which includes records of all illness/absences in excess of five days. Age adjusted annual morbidity frequency rates and annual durations of absence are presented by age, sex, job, and work status. Generally, rates and durations of absence were highest for older age groups, women, and production workers. Increased risk was associated with the presence of known disease risk factors. Overall, 48% of the employees had at least one illness/absence in excess of five days during the eight year period. Twelve per cent of the employees had four or more absences, which accounted for 54% of the total number of absences and 52% of the total work days lost. Among men, the five most common conditions accounted for 72% of all illness/absences. In descending order they were injuries (25%), respiratory illnesses (17%), musculoskeletal disorders (14%), digestive illnesses (9%), and heart disease (7%). Similar patterns were noted among women. These findings may be useful in setting priorities and directing efforts such as health education programmes and other strategies for the prevention of disease.

Absenteeism↗

PubMed1991

Morbidity patterns among employees at a petroleum refinery.

This study examined the morbidity experience of a prospective cohort of 2132 male employees who worked at a petroleum refinery from 1981 through 1988. The morbidity data included all illness-absence episodes in excess of 5 days during the study period. Standardized morbidity ratios (SMRs) of disease prevalence were calculated using data from all manufacturing employees of the Shell Oil Company as an internal comparison group. As such, there is no potential bias associated with the "healthy worker effect" in this type of study design. Morbidity for all causes combined was virtually the same as that for the comparison group with 2,311 observed and 2,318 expected disease prevalence events. However, there were statistically increased prevalence of musculoskeletal system disorders (SMR = 136) and injuries (SMR = 125) among staff employees and skin and subcutaneous tissue disorders (SMR = 138) among production employees. A review of the original morbidity reports for these skin conditions revealed that none were due to exposure to chemical products or solvents. The SMR for neoplasms of the lymphatic and hematopoietic tissue among production employees was slightly elevated but was based on only three cases (2.4 expected). Of the three cases, none was due to leukemia.

Adult↗

PubMed1991

Medical surveillance for leukemia at a petrochemical manufacturing complex: four-year summary.

Four-year results are presented on 2086 participants of a medical surveillance program of current and retired employees at a manufacturing complex in Illinois. Annual complete blood cell count testing and intensive follow-up of all out-of-normal-range results began in 1985 on a voluntary basis. The program to date has not identified any evidence for an unusual distribution of out-of-range complete blood cell count results. Active employees with out-of-range complete blood cell count values had no increase in adverse health outcomes compared with those with in-range values. Retired employees with out-of-range values were more likely to have a serious underlying medical condition, but this appeared to be more a function of age than of occupational exposure. Four cases of myelodysplastic syndrome were brought to our attention as a result of the program, but there is no similarly followed population available for comparison to determine whether this represents an increase over expected cases. The lack of correlation of out-of-range complete blood cell count results in active employees with serious hematologic disease raises significant questions about the utility of such surveillance for chemically exposed groups (eg, benzene-exposed workers) when exposure levels are low and well controlled.

Adult↗

PubMed1990

Smoking and morbidity frequency in a working population.

As part of Shell's health surveillance program, morbidity frequency and severity by smoking status (current smoker, exsmoker, nonsmoker) were compared for the 3-year period 1985 through 1987. Morbidity data for this study were extracted from the morbidity section of the Shell Health Surveillance System, which included all illness and absence events in excess of 5 days. Statistically significant positive associations were seen between smoking habits and overall morbidity, diseases of the circulatory system, and diseases of the respiratory system for both male and female employees. In addition, a significantly increased association between smoking and both non-motor vehicle accidents and motor vehicle accidents among current smokers was noted. Current smokers had a greater than 60% higher frequency rate (P less than .05) for non-motor vehicle accidents than nonsmokers for both men and women. Male smokers also had a 75% increased (P less than .05) motor vehicle accident rate. These results suggest that it may be possible to reduce overall illness and injury morbidity through implementation of successful smoking cessation programs.

Accidents, Occupational↗