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Background: Chronic heat stress and dehydration from strenuous work in hot environments is considered an essential component of the epidemic of chronic kidney disease in Central America., Objective: (1) To assess feasibility of providing an intervention modelled on OSHA's Water.Rest.Shade programme (WRS) during sugarcane cutting and (2) to prevent heat stress and dehydration without decreasing productivity., Methods: Midway through the 6-month harvest, the intervention introduced WRS practices. A 60-person cutting group was provided water supplied in individual backpacks, mobile shaded rest areas and scheduled rest periods. Ergonomically improved machetes and efficiency strategies were also implemented. Health data (anthropometric, blood, urine, questionnaires) were collected preharvest, preintervention, mid-intervention and at the end of harvest. A subsample participated in focus group discussions. Daily wet bulb globe temperatures (WBGT) were recorded. The employer provided individual production records., Results: Over the harvest WBGT was >26°C from 9:00 onwards reaching average maximum of 29.3±1.7°C, around 13:00. Postintervention self-reported water consumption increased 25%. Symptoms associated with heat stress and with dehydration decreased. Individual daily production increased from 5.1 to a high of 7.3 tons/person/day postintervention. This increase was greater than in other cutting groups at the company. Focus groups reported a positive perception of components of the WRS, and the new machete and cutting programmes., Conclusions: A WRS intervention is feasible in sugarcane fields, and appears to markedly reduce the impact of the heat stress conditions for the workforce. With proper attention to work practices, production can be maintained with less impact on worker health., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

A lung cancer case-control study was conducted in a Slovenian asbestos-cement factory for which unusually good records of asbestos exposures were available. The cohort consisted of all 6714 workers employed at the Salonit Anhovo factory after 31 December 1946 who worked there for at least one day between 1964 and 1994. Fifty-eight histologically confirmed cases of primary lung cancer and 290 controls were selected from the cohort. Working life exposure histories to amphibole and chrysotile forms of asbestos were estimated separately. Airborne asbestos concentrations were low. For example, the arithmetic mean exposure to all forms of asbestos in the highest exposure period (1947-1971) was 1.2 f/cm(3). Chrysotile asbestos made up about 90% of this exposure (mean 1.1 f/cm(3)), whereas amphibole accounted for 10% (0.1 f/cm(3)). Comparing those above and below the 90 percentile of cumulative exposure, the odds ratios for all asbestos, chrysotile and amphibole were 1.5, 1.6 and 2.0, respectively, but confidence intervals were wide. There are only a few asbestos-lung cancer studies with high-quality exposure data and exposures in this low range. Though imprecise, the findings are important to the ongoing debate about asbestos risks.

Aims: To estimate the one year cumulative incidence and persistence of upper extremity (UE) soft tissue disorders, in a fixed cohort of automotive manufacturing workers, and to quantify their associations with ergonomic exposures., Methods: At baseline and at follow up, cases of UE musculoskeletal disorders were determined by interviewer administered questionnaire and standardised physical examination of the upper extremities. The interview obtained new data on psychosocial strain and updated the medical and work histories. An index of exposure to ergonomic stressors, obtained at baseline interview, was the primary independent variable. Cumulative incidence and persistence of UE disorders (defined both by symptoms and by physical examination plus symptoms) were analysed in relation to baseline ergonomic exposures, adjusting for other covariates. The incidence of new disorders was modelled using multivariate proportional hazards regression among workers who were not cases in the first year and the prevalence on both occasions was modelled by repeated measures analysis., Results: A total of 820 workers (69% of eligible cohort members) was examined. Follow up varied slightly by department group but not by baseline exposure level or other characteristics. Among the non-cases at baseline, the cumulative incidence of UE disorders was 14% by symptoms and 12% by symptoms plus examination findings. These rates increased with index of physical exposures primarily among subjects who had the same jobs at follow up as at baseline. Increased exposure during follow up increased risk of incidence. The persistence of UE disorders from baseline to follow up examination was nearly 60% and somewhat associated with baseline exposure score., Conclusions: These longitudinal results confirm the previous cross sectional associations of UE musculoskeletal disorders with exposure to combined ergonomic stressors. The exposure-response relation was similar for incident cases defined by symptoms alone and those confirmed by physical examination.

Aims: To re-examine aerodigestive cancer risk in a cohort of autoworkers exposed to metal working fluids (MWF), using improved case definition and more recently diagnosed cases., Methods: The autoworker cohort included 31 100 hourly workers alive on 1 January 1985 who worked at three automobile plants in Michigan. A case-cohort design was carried out that included incident cases of cancers of the larynx, oesophagus, and stomach, and a 10% sample of the cohort. A Cox proportional hazards model was used to estimate MWF exposure effects. The smoothing method of penalised splines was used to explore the shape of the underlying exposure-response curves., Results: The most important finding was the association between larynx cancer incidence and cumulative straight MWF exposure. The results for oesophageal cancer were less consistent. For stomach cancer there was no evidence of excess risk., Conclusion: This association between larynx cancer and straight MWF exposures was consistent with a previous finding in this cohort, providing further support for a causal relation.

Aims: To determine chronic effects of long term exposure to cotton dust and endotoxin on incidence of respiratory symptoms and the effect of cessation of exposure., Methods: Respiratory health in 429 Chinese cotton textile workers (study group) and 449 silk textile workers (control group) was followed prospectively from 1981 to 1996. Byssinosis, chest tightness, and non-specific respiratory symptoms were assessed by means of identical standardised questionnaires at four time points. Exposures to cotton dust and endotoxin were estimated using area samples collected at each survey. Incidence and persistence of symptoms were examined in relation to cumulative exposure and exposure cessation using generalised estimating equations (GEE)., Results: Among cotton workers, the cumulative incidence of byssinosis and chest tightness was 24% and 23%, respectively, and was significantly more common in smokers than in non-smokers. A high proportion of symptoms was found to be intermittent, rather than persistent. Among silk workers, no typical byssinosis was identified; the incidence of chest tightness was 10%. Chronic bronchitis, cough, and dyspnoea were more common and persistent in the cotton group than in the silk group. Significantly lower odds ratios for symptoms were observed in cotton workers who left the cotton mills; risk was also related to years since last worked. Multivariate analysis indicated a trend for higher cumulative exposure to endotoxin in relation to a higher risk for byssinosis., Conclusion: Chronic exposure to cotton dust is related to both work specific and non-specific respiratory symptoms. Byssinosis is more strongly associated with exposure to endotoxin than to dust. Cessation of exposure may improve the respiratory health of cotton textile workers; the improvement appears to increase with time since last exposure.

An investigation of the acute respiratory effects of workers exposed to metal working fluids (MWF) was conducted in an automobile parts manufacturing facility. After observing an association between cross-shift decline in forced expiratory volume in the first second (FEV1) and aerosol mass concentration, improved characterization of the exposure was sought through investigation of four elements of a priori interest (Cl, Cr, Ni, S). Of these, only sulfur showed an association with cross-shift FEV1 decrement. The relative risk of 5% cross-shift FEV1 decrement was 2.7 (95% confidence interval = 1.0-6.0) comparing those with > 4.4 micrograms/m3 to those with < 2.5 micrograms/m3 sulfur exposure. Because the concentrations of sulfur in this environment were relatively low and other respiratory irritants were present, sulfur is more likely to be an indicator of more irritating conditions than the sole agent responsible for the observed acute respiratory effects.

This report describes the reanalysis of a cross-sectional study of asthma in a large cohort of autoworkers with exposure to metalworking fluids (MWF). There is strong evidence from case reports, clinical studies, and medical surveillance data that exposure to MWF can cause asthma, yet no association was found in the original analysis. The central hypothesis of the reanalysis was that the absence of an association between asthma and MWF exposure was the result of bias caused by the self-selection of asthmatics out of exposed jobs. We addressed the potential job transfer bias by redefining exposure and disease status at the time of asthma onset, rather than at the time of the health survey. This permitted us to treat the cross-sectional study as if it were a historical cohort study, despite the fact that the population was a biased sample of the full cohort. This approach resulted in a significantly elevated incidence rate ratio of 3.2 (95% CI: 1.2-8.3) for synthetic MWF estimated in a Cox proportional hazards model. Although the cross-sectional design makes it impossible to document or control for differential selection out of the workforce, the approach described here provides a strategy for reducing the healthy-worker effect due to job transfer bias in cross-sectional studies.

This study examined work-related chronic abnormality in pulmonary function and work-related acute irritant symptoms associated with exposure to borate dust in mining and processing operations. Chronic effects were examined by pulmonary function at the beginning and end of a 7-year interval. Time-specific estimates of sodium borate particulate exposures were used to estimate cumulative exposure during the study interval. Change in pulmonary function over the 7 years was found unrelated to the estimate of cumulative exposure during that interval. Exposure-response associations also were examined with respect to short-term peak exposures and incidence of five symptoms of acute respiratory irritation. Hourly measures of health outcome and continuous measures of particulate exposure were made on each subject throughout the day. Whenever a subject reported one of the irritant symptoms, a symptom intensity score was also recorded along with the approximate time of onset. The findings indicated that exposure-response relationships were present for each of the specific symptoms at several symptom intensity levels. The associations were present when exposure was estimated by both day-long and short-term (15-min) time-weighted average exposures. Associations persisted after taking account of smoking, age, and the presence of a common cold. No significant difference in response rate was found between workers exposed to different types of sodium borate dusts.

To address earlier reports of excess cancer mortality associated with employment at a large transformer manufacturing plant, each plant operation was rated for seven exposures: Pyranol (a mixture of polychlorinated biphenyls and trichlorobenzene), trichloroethylene, benzene, mixed solvents, asbestos, synthetic resins, and machining fluids. Site-specific cancer deaths among active or retired employees were cases; controls were selected from deaths (primarily cardiovascular deaths) presumed to be unassociated with any of the study exposures. Using job records, we then computed person-years of exposure for each subject. All subjects were white males. The only unequivocal association was that of resin systems with lung cancer (odds ratio = 2.2 at 16.6 years of exposure, P = 0.001, in a multiple logistic regression including asbestos, age, year of death, and year of hire). Certain other odds ratios appeared larger, but no other association was so robust and remained as distinct after considering the multiplicity of comparisons. Study power was very limited for most associations, and several biases may have affected our results. Nevertheless, further investigation of synthetic resin systems of the type used in the study plant appears warranted.

Field studies of occupational exposure to airborne irritants have predominantly relied on symptom surveys of study participants. As part of a new approach to the study of acute irritant symptoms, subjects exposed to sodium borate dusts recorded their symptom responses at hourly interviews as well as instantaneously on an electronic device called an event marker. Overall, the unprompted marks indicated fewer irritant events than the interviews. Marks were more frequent in the presence of more than one type of symptom and also appeared to reflect more severe symptoms. A proportion of the marked events occurred in time intervals when no symptoms were recalled during the interview. The exposure-response relations were similar regardless of whether they were based on the interview reports or the electronically marked symptoms. The event marker provided a means to examine the time of onset of the acute symptom event. It also made it possible to examine directly the timing profiles of symptom response in relation to changes in exposure levels in a field setting. Despite some inconsistencies, the finding suggests that the event marker may provide an alternative to frequent interviews of exposed workers to obtain irritant symptom responses for exposure-response modeling.

Investigation of the use of PEF in the measurement of airway variability over a single day or several weeks suggests that serial measures of PEF may prove useful in detecting short-term adverse responses to a variety of environmental agents. Several investigators have already shown how the visual inspection of temporal trends can prove useful in identifying individuals with occupational asthma. The use of statistical summaries of diurnal variation, i.e., the amplitude as a percent of the daily mean, may provide important added information about airway reactivity in response to occupational exposures in a variety of populations. Indeed, there are several groups of investigators presently examining more refined ways, including autoregressive time series models, of linking short-term temporal patterns in serial measurements of PEF with simultaneously measured short-term exposures. As our understanding of the sources and nature of the variability in PEF improves, together with refinements in the statistical techniques used to describe the temporal data, serial measures of PEF are likely to see a far broader application in the study of acute respiratory hazards. Does the utility of PEF as a pulmonary function measurement stem solely from ease of collection and the consequent increase in the amount of data one can gather, or is the PEF a distinctly different and inherently useful measure of pulmonary function? This question cannot yet be answered. The increasing availability of accurate reliable hand-held spirometers means that one can now plan studies using the powerful repeated measures designs previously feasible only with the peak flow meter (see article on Instrumentation, pp 397-408, in this issue). These data will enable side-by-side comparisons of PEF, FEV1, maximum mid-expiratory flow, and other parameters collected simultaneously. Will the FEV1 once again become the preferred measure of airflow? Time will tell.

This presentation reviews occupational epidemiology as a foundation for workplace disease prevention activities. By examining descriptive, etiologic and intervention occupational epidemiology studies, a range of opportunities are illustrated where epidemiology has played, or could play a principal role in guiding preventive efforts. Descriptive studies presented include ones based on vital records, on epidemic investigations, cross-sectional surveys, and surveillance. Etiologic studies review the largely successful development of knowledge for lung cancer and asbestos exposure for pulmonary effects of isocyanate exposures. However, attention is also directed to the need for etiologic studies of work environment risks for both cardiovascular and musculoskeletal disease. Finally importance is placed on the too infrequent epidemiologic studies of intervention. Historical examples of control of large risks from nickel cancers and silicosis are balanced with more recent examples of successes at reducing smaller risks of cardiovascular disease and oil acne. Throughout, emphasis is placed on the importance of reintegrating the academic discipline of epidemiology into the application of study findings to prevention of workplace risks.

We present an epidemiologic approach for the study of the irritant effects of sodium borate exposure that can be used to study acute reversible health effects more generally. Acute irritant responses, such as symptoms of nasal irritation or cough, are subjective. They may, however, be accompanied by transient airway obstruction, which can be objectively measured by a change in peak expiratory flow (PEF) or forced expiratory volume in one second (FEV1). Because these physiologic responses are reversible and follow short-term peaks of exposure, they cannot be studied effectively using conventional epidemiologic methods of design and analysis. The proposed study design is a short-term prospective cohort study with frequently repeated measures of health effects and simultaneous measures of exposure. Because each subject passes through periods of high and low short-term exposure, the study has the form of a crossover design. This design permits each acute response to be linked to the corresponding short-term average exposure, providing the data necessary for dose-response analyses within subject. We present the results of the sodium borate study to illustrate the analysis of such data.

Where have we come since the Occupational Safety and Health Act was passed in 1970? Have we made progress in this country toward "safe and healthful working conditions for working men and women?" Many hazardous exposures that were prevalent before the creation of NIOSH, OSHA, and MSHA have been reduced. Exposure to asbestos, coal dust, silica, lead, and cotton dust are common examples. Through OSHA's Hazard Communication Standard and state Right to Know laws as well as an increase in the dissemination of information, the average employer and worker today is better informed of specific hazards on the job, and more attentive to safety measures. However, the high toll of work related disease and injuries continues today.

A Health Hazard Evaluation was conducted by the National Institute for Occupational Safety and Health in an area of a large chemical plant that manufactured the stilbene derivative 4,4'-diaminostilbene-2,2'-disulfonic acid, an intermediate used for the production of optical brightening agents. Men employed in the area reported problems with impotence. The study population consisted of 44 men aged 20-57 years (mean age 37) employed in the area at the time of the evaluation. An industrial hygiene investigation, health and work history questionnaire survey, physical examinations, and blood chemistry and serum hormone evaluation were conducted. Fourteen percent of the men reported symptoms of impotence over the preceding 6 or more months, 7% had potency problems of shorter duration, and 7% were not currently impotent but had experienced impotence for 6 or more months in the past; 36% experienced decreased libido, all since beginning work in the production area. Low levels of serum testosterone (less than 350 ng/dl) were observed in 37% of the men. The low serum testosterone concentrations were not accounted for fully by diurnal variation or an effect of rotating shift work. It is suggested that exposures to chemicals possessing estrogenic activity may be related to the observed health effects in these workers.

Fumes from solder flux have been shown to cause asthma among solderers in a British electronics factory. In the present study, questionnaires and lung spirometry were administered to 104 U.S. electronics workers (93 women, 11 men) who soldered printed circuit boards. Two types of solder flux were used: 68 subjects had worked only with a rosin-core (colophony) solder; 36 had changed from rosin- to an aqua-core ("phosphorous hexate") solder 15 months before the study. Symptoms of eye, throat, and nose irritation occurred in nearly half of the total group. Lower respiratory tract symptoms, including cough, phlegm production, and wheezing, also occurred with increased frequency, compared with reported rates among a general population. Similar symptom rates were observed among the aqua- and rosin-core groups. That these symptoms were work related was indicated by the subject's improvement on weekends or during vacation periods. On average, lung spirometry performed before starting work on Monday mornings showed no impairment in lung function; over the course of the work day there were small decrements in the forced expiratory volume at 1 s (mean, -21 +/- 11 [SD] ml) and forced vital capacity (-30 +/- 145 ml), but these decrements were unrelated to the individual amounts of solder used during the same period. Among the white female workers (N = 83), several multivariate analyses indicated that an increase in the amount of soldering had a beneficial effect on lung function, particularly among those who currently smoked. This paradox probably resulted from a "healthy worker effect" resulting from some individuals with lower than average lung function who left the industry early in the course of their employment.

Neurogenic bladder dysfunction, characterized by hesitancy, need to strain, decreased stream, and increased duration of urination, developed in 104 (63%) of 166 employees working in the manufacture of polyurethane foam. Highest rates of illness (69%) occurred in production workers, and no illness occurred in office or warehouse workers. Onset of the epidemic coincided with introduction of a catalyst, dimethylaminopropionitrile (DMAPN), and monthly case incidence rates increased as DMAPN use increased. Outbreak ceased abruptly when DMAPN use was stopped. Of eight patients who underwent neurourologic testing during recovery, seven lacked either detrusor reflex or normal sensation of bladder filling; seven had a subclinical sensory abnormality; three had prolonged sacral-evoked responses; and two of these three had limb motor neuropathies. Dimethylaminopropionitrile is unique among known neurotoxins in producing urinary symptoms more frequently than limb nerve symptoms.

This paper reviews the known respiratory effects of isocyanates. There is good evidence to indicate that isocyanates: cause chemical bronchitis/pneumonitis; are potent pulmonary sensitizers capable of causing "isocyanate asthma"; cause nonspecific airways disease, including chronic bronchitis; can induce a general asthmatic state; and can cause hypersensitivity pneumonitis. Similar dose-response relationships are seen for both acute and chronic effects. There are plants operating in which exposures are well controlled and in which no respiratory effects can be detected. Suggestions are provided for preplacement assessment and periodic surveillance for workers exposed to these compounds.

In this cross-sectional investigation of female garment workers the prevalence of soft tissue disorders of the hands and arms was studied. The findings were compared with the prevalence of disorders in a group of female hospital employees not required to use repetitive hand motion. One hundred and eighty-eight garment workers and 76 hospital employees were surveyed by questionnaire and physical examination. The prevalences of persistent shoulder, wrist, and hand pain were significantly greater among the garment workers (rate ratio 2, 4, and 3, respectively). In both groups about 60% of the persistent hand pain was consistent with carpal tunnel syndrome (rate ratio 3). These associations held when the comparisons were stratified by age and by length of employment. Workers whose native language was not English were significantly less likely to report symptoms (rate ratio 0.6). Workers in hand sewing and trimming suffered especially high prevalences of persistent pain in all upper limb sites. Stitchers had elevated rates of pain in the shoulders, wrists, and hands. Workers ironing by hand had a significant elevation in elbow pain rates. Garment assembly tasks appear to be associated with cumulative trauma of the hands and wrists; the biomechanical features of these jobs should be studied in greater detail.

An interactive computer program which computes the standardized mortality odds ratio and the standardized proportional mortality ratio has been developed for use in the analysis of occupational mortality studies. The program provides flexibility in the selection of the comparison (unexposed) population, permitting both internal and external comparison, including comparison with the United States general population. Considerable control for potential confounding factors and for differences in information collection procedures can be exercised through careful choice of the comparison population. The user must select the reference cause(s) of death among 55 categories (59 for women). The condition for equivalence of the standardized mortality odds ratio and the standardized mortality ratio will be met when the selected reference cause(s) is unrelated to the exposure. The program reduces the loss of information due to sparse data during stratification by allowing the user to define the length of the age and time intervals. The program is written in Fortran IV and is designed to produce rapid, cost-efficient interactive results on any mainframe computer system.

Findings are reported from a prospective morbidity study which examined the effects on pulmonary function associated with the particulate and gaseous air contaminants to which retail food store workers are exposed. A total of 685 supermarket employees (including meat wrappers, meat cutters and store clerks) performed standard ventilatory function tests [forced expiratory volume in 1 s (FEV1.0) and forced vital capacity (FVC)] during a base-line survey. Those available four years later (305) were resurveyed in a similar manner. A suggestive chronic effect on pulmonary function was shown in those with high cumulative exposures and allergic history. Among those workers who had continuous exposure to air contaminants in settings with "hot-wire" plastic wrap film cutters the annual rates of change in FEV1.0 and FVC were twice as great as the changes found among comparable workers who were not exposed to fumes from wrapping film. Those who switched from the "hot-wire" to the "cool-rod" cutters during the course of the follow-up had intermediate rates of change in lung function.

This study examined the relationships between the prevalence of respiratory tract symptoms and estimates of environmental exposures in retail food stores, in particular exposures to emissions from the cutting of polyvinyl chloride wrap. When respiratory symptoms were compared with a measure of cumulative exposure, there was evidence that the prevalence of symptoms of episodic airway narrowing was higher for workers who had been exposed directly or indirectly to meat wrapping operations independent of a significant association of these symptoms with allergic or asthmatic history. Whether this finding reflects a nonspecific irritant effect or allergic sensitization cannot be determined from these data. No single substance present in the work environment studied has, as yet, been identified as associated with these effects.

A mortality odds ratio (MOR) study has been conducted to explore the cancer risks of exposures experienced in the production of optical lenses and metal spectacle frames. Male death certificates were obtained from a Massachusetts town where a large optical industry is located. Craftsmen, foremen, and operatives of non-optical industries, such as woollen textile workers and workers in the optical company with short-term or no exposure, were chosen as reference workers their incomes were similar to those of the exposed workers. Cardiovascular disease (total 714) is chosen as the reference disease to explore cancers (total 232). An excess risk of total cancers observed = 70, expected = 48) has formed among lens workers. The excess may be accounted for mainly by the excess risk of gastrointestinal cancers; the standardised MORs (sMOR) for medium and long-term exposure were 2.2 and 2.5. The excess was especially evident for colorectal cancers; the sMORs for medium and long-term exposures were 3.2 and 2.6. Excess risks of gastrointestinal cancers (sMOR = 2.9) and colorectal cancers (sMOR = 3.4) were found among metal frame workers with long-term (employed for more than 29 years) exposure, but the number of exposed cases was small (9 and 6 respectively). These results suggest that exposure to abrasives or cutting oil mists or both, possibly by ingestion, might increase the risk of gastrointestinal (especially colorectal) cancers among lens and metal spectacle frame manufacturers.

Exchanges between U.S. and Chinese professionals have provided opportunities for observation of recent developments in occupational health in China. For the past decade, China has been committed to an unprecedented drive for economic modernization, including new policies on ownership, business management, employment, health care, and disability as well as increased activity in heavy, light, and service industries. Chinese occupational health professionals and labor organizations have set a goal of modernizing worker health along with the rest of society. Examples of advances in occupational health occurring since 1981 are the coordination of industrial hygiene and health research and services, an emphasis on epidemiology, interdisciplinary approaches to problem-solving, the pretesting of toxic substances, regulation and standard setting, and on-site workplace hazard prevention.

This study examines cancer mortality patterns by occupation for white males in Massachusetts using 1971-1973 death records. Its purpose is to identify occupation-cancer associations that, when interpreted in conjunction with results from other studies and hypotheses about potential occupational carcinogens, can serve as leads for more definitive etiological investigations. Sixty-two malignancy categories (including grouped categories) were investigated for each of 397 occupational categories (including grouped categories) using an age-standardized mortality odds ratio approach. An important finding was the association between lung cancer and a large number of occupations for which there is support from other epidemiologic studies and/or for which there are reasonable hypotheses as to possible carcinogenic exposures. These occupations include truck drivers, painters, machinists, automobile mechanics, plumbers, cooks, fishermen, heated metal workers, sheet metal workers, and brickmasons/stonemasons/tile setters.

This paper describes our experience with the respiratory effects of TDI. Five respiratory reactions attributable to TDI are described with supporting evidence. The reactions are sensitization, irritation from overexposure, acute loss of ventilatory capacity, accelerated loss of pulmonary function and induction of a general asthmatic state. Evidence is presented that suggests a safe exposure level.

The lack of successful disease surveillance methods has resulted in few reliable estimates of workplace-related disease. Hazard surveillance--the ongoing assessment of chemical use and worker exposure to the chemicals--is presented as a way to supplement occupational disease surveillance. Existing OSHA (Occupational Safety and Health Administration) and NIOSH (National Institute for Occupational Health) data systems are adapted to this function to characterize the distribution and type of hazardous industry in Los Angeles County. A new method is developed for ranking potentially hazardous industries in the county using actual exposure measurements from federal OSHA compliance inspections. The strengths of the different systems are presented along with considerations of industrial employment and types of specific chemical exposures. Applications for information from hazard surveillance are discussed in terms of intervention, monitoring exposure control, planning, research, and as a complement to disease surveillance.

We have reviewed existing data sources available for conducting hazard surveillance. Both the NIOSH NOHS/NOES and the OSHA IMIS can have significant value for hazard surveillance that is designed both to establish priorities for various preventive strategies--including intervention, research, and planning--and to complement disease surveillance. These systems also have certain limitations that affect their overall value in these regards. We have proposed alternative hazard surveillance systems that would expand the database on actual exposures in the workplace by requiring that industry systematically conduct environmental monitoring for defined substances and then provide the data to OSHA and NIOSH for use in hazard surveillance.

Recent studies identify digestive cancer excesses among workers exposed to cutting fluids, abrasive dusts, and oil smoke. Standardized proportional mortality and mortality odds ratio studies were carried out for a ball bearing plant. Cause of death and work histories were obtained for 702 of 768 hourly employees with ten or more years' service who died between 1969 and 1982. Union and company records were used to define exposure measures. The major findings were significant excesses in proportional mortality ratios (PMR) from stomach cancer (PMR = 2.0) and rectal cancer (PMR = 3.1) among white men. After control for age at death, there was a significant association between stomach cancer and precision grinding exposures, consisting primarily of direct contact with water-based cutting fluids (usually emulsified oils) and their aerosols. Some straight oils and synthetic cutting fluids were used as well. The pattern of stomach cancer is consistent with previous findings and suggests an association with the soluble oil cutting fluids.

Analysis of the causes of death among workers employed in the manufacture of synthetic abrasive products was performed using data from death certificates and employment records. The subjects were 1,030 white male workers who had been employed by a single manufacturer and who were identified through a review of death certificates issued during a 20-year period. Proportional mortality analysis revealed excess digestive cancer and respiratory disease deaths. Personnel records permitted refinement of the study population to 968 with classification of each individual into one of seven employment categories. Case-control analysis of workers ever employed in the individual categories revealed elevated odds ratios for respiratory disease deaths among those most exposed to the synthetic abrasive dust. The excesses were greatest in those exposed 20 or more years. Excesses of esophageal and rectal cancers were noted in two manufacturing areas although the numbers were small. Review of the literature further supports the findings that synthetic abrasive exposures may be associated with elevated respiratory morbidity and mortality.

The relationships between occupation, smoking, and the three most common histologic types of lung cancer (squamous cell carcinoma, small-cell carcinoma, and adenocarcinoma) were explored in a case-control study with the use of data collected during the Third National Cancer Survey. The largest histologic group was squamous cell carcinoma (152 cases), followed by adenocarcinoma (50 cases), and small-cell carcinoma (45 cases). The control series was comprised of cancers at all anatomic sites except those believed to be associated with either smoking or occupational exposures. Cigarette smoking was significantly associated with all three histologic types of lung cancer. Overall, the relationship with small-cell carcinoma was strongest (odds ratio = 5.1), whereas those with squamous and adenocarcinoma were approximately equivalent (odds ratio = 3.1). Dose-response relationships were evident for all three histologic types; however, the linear relationship was found to be statistically significant (P less than 0.05) only for squamous and small-cell carcinomas. Squamous cell carcinoma was the type most frequently associated with occupational categories. It was significantly associated (P less than 0.05) with "blue collar" professions (odds ratio = 2.1). No occupational categories were significantly associated with adenocarcinoma. In addition, no occupational categories were associated with all histologic types of lung cancer combined. This last observation suggested that the sensitivity of epidemiologic studies might not only be increased by use of improved occupational histories but more specifically by consideration of histology in examination of associations between occupation and respiratory cancer.

During the period of an "energy crisis" in 1974, two workers in a textile printing plant in Massachusetts developed clinical manifestations of encephalopathy. Both had evidence of bone marrow injury and one had pancytopenia. Study of their work environment revealed that they had ethylene glycol monomethyl either (EGMME) poisoning primarily due to cutaneous exposure. EGMME was used as a cleansing agent as a substitute for acetone, which was unavailable due to temporary shortage. Proper product labels could have prevented the illness.

The overall number of deaths from cancer is increasing. The absolute magnitude of this increase is in debate. Unfortunately, we are unable to estimate the interactions between two or more agents such as cigarettes and asbestos. None of the appropriate studies is precisely able to know the exact exposure to carcinogens. Regardless of the percentage of cancers related to the workplace, the numbers are clearly clinically significant. It is important to present to physicians medical conditions which have an increased probability of resulting from occupational exposure. This will allow clinics, hospitals and health departments to seek evidence of changing patterns or clusters of listed diseases. Individual physicians with a high index of suspicion play an important role in detecting occupational cancers. The current state of the art is, that with rare exceptions, a good occupational history which contributes to a reasonable diagnosis with appropriate background information is the best way for the practicing doctor to detect occupational cancers. All health care providers should look beyond cigarettes as the only cause of cancer worth noting in order to implement primary preventive medicine strategies.

In a study of the chronic effects of fire fighting on lung function, 1,768 employees from the Boston Fire Department were examined in 1970. From this cohort, 109 firefighters who retired in the period 1970 to 1975 have been restudied with questionnaire and ventilatory function tests. The observed vulues for pulmonary function when expressed as a per cent of predicted are consistently slightly below 100 per cent. The expected effect of cigarett smoking on lung function was demonstrated. The results suggest thetirement) are important in reducing the effect of fire fighting on subjects who may be adversely affected by the inhalation of combustion products.

One hundred forty-four sewing machine operators answered questionnaires concerning occupational history and musculoskeletal symptoms adapted from the National Health and Nutrition Examination Survey. They were matched for age within 5 years, race, and sex with persons completing the HANES I Augmentation Survey, and the prevalence of self-reported musculoskeletal morbidity was compared. Operators complained significantly more often of knee pain (prevalence odds ratio [POR] = 1.84, p = .0001) and knee swelling (POR = 9.98, p less than .00001), although they were no more likely to have had knee surgery. Similar increases were reported for upper-back pain (POR = 2.13, p = .002) joint ache, and joint swelling (both were significant for fingers, wrists, elbows, and shoulders at p less than .05 levels). No differences in low-back pain or in hospitalization for joint conditions were noted. Ergonomic redesign of sewing machines needs to address knee and upper-back movements as well as the arm, wrist, and finger movements.

A proportional mortality analysis of jewelry workers as identified on death certificates is presented. The study group consisted of 931 males who died in Attleboro, Mass., between 1956 and 1975. An excess proportion of pancreas cancer was found in the entire group (16/9; p < 0.05) and was not explained by ethnic or other non-occupational factors. Job titles were specific enough to identify a subset of polishers and findings for this job category were compared to those for all other categories. Excesses of stomach cancer (odds ratio 4.4; p < 0.01) and stomach ulcer (odds ratio 5.0, p < 0.01) were found, but for each the observed number of deaths is small. Possible important exposures in the jewelry industry are reviewed.

Following a 1978 outbreak of bladder neuropathy among workers exposed to dimethyl-aminopropionitrile (DMAPN), follow-up studies were performed 2 a after the original epidemic to evaluate the persistence of symptoms among a small group of initially affected workers. Although the overall prevalence of urologic and neurological symptoms fell for the 11 persons interviewed, significantly high rates of persistent symptoms were seen. Of particular concern was the increase in the prevalence of symptoms of sexual dysfunction. Physical examination identified one individual with sensorimotor neuropathy which was initially detected 2 a earlier. Three individuals who had similar neuropathic findings in 1978 were normal 2 a later. Objective neurophysiological and urologic testing revealed evidence of persistent abnormalities in several workers, but most of the objective findings had improved over the 2-a period. The follow-up of residual effects of occupational exposure to neurotoxic substances is essential to the understanding of the course of occupational illnesses.

Miners and millers of talc ore, free from asbestos and silica, were examined for respiratory effects. A study of 116 subjects included the modified British Medical Research Council respiratory symptom questionnaire, simple spirometry, chest radiography, and limited examination of the chest. A one-year follow-up evaluation was performed on 103 subjects. Of the 12 subjects whose chest radiographs showed small round or irregular opacities (perfusion 1/0 or greater), five had never smoked cigarettes. Pulmonary function values at the time of the initial study were less than predicted and the rates of loss of FEV1 and FVC greater than expected. These differences were in part attributed to cigarette smoking but were greater than predicted from that source alone. There was evidence of an exposure effect after adjusting for cigarette smoking and we conclude that these workers have been affected by their exposures. No clear interaction between smoking and exposure could be identified. Populations such as this will need to be studied for longer periods to determine what current dust levels are safe.

Granite workers lost to follow-up during a 5-yr study of pulmonary function were examined. We found that in workers who had left the industry for other employment, forced expiratory volume in one second (FEV1) values declined at a faster rate than in those who remained employed or retired during the study period. We investigated the application of a currently recommended repeatability criterion for pulmonary function tests by looking at different patterns of failing to satisfy the criterion (PFT-failure) over multiple testing sessions. Workers with persistent PFT-failure were found to have faster rates of FEV1 decline than did subjects with none or only intermittent failures. In a regression analysis, job termination was found to be more strongly associated with a steep FEV1 slope when it had been preceded by a pattern of persistent PFT-failure.

Several population data bases were used to generate hypotheses about associations between colorectal cancer and workplace exposures. The Third National Cancer Survey interview sample was used to select 343 male and 208 female cases and 626 male and 1,235 female cancer controls. Potential work exposures were assigned with the use of data from the National Institute for Occupational Safety and Health National Occupational Hazard Survey. Dietary factors were modeled from the National Health and Nutrition Examination Survey data. Work-related stress was considered with the use of a model based on the U.S. Department of Labor's Quality of Employment Survey. Other risk factors included age, race, ponderosity, and menopausal status. Logistic analysis yielded hypotheses for colon cancer risk in males with potentially high exposure to solvents, abrasives, and fuel oil and in those in jobs with high demand and low control (high "stress"). Hypotheses emerged for females with potentially high exposure to dyes, solvents, and grinding wheel dust.