Mortality and cancer incidence in stockholm fire fighters

Fire fighters are exposed to irritating, asphyxiating, and toxic gases and aerosols, to psychological stress, and to physically demanding work. Due to differences in fire fighting techniques, exposure conditions for fire fighters differ among different countries. The purpose of this investigation was to study cancer incidence and mortality in fire fighters who have been working with fire fighting methods used in Sweden from the beginning of this century onwards. All male fire fighters employed for at least 1 year in the City of Stockholm during 1931–1983 were traced, and an index of the number of fires fought was calculated for each individual. The mortality during 1951–1986 (among 1, 116 fire fighters) was lower than expected (SMR = 82; 95% confidence interval 72–91) compared with local mortality rates, with a low mortality in circulatory diseases, obstructive lung diseases, violent deaths, and suicides. The cancer incidence in 1958–1986 was equal to the expected (SMR = 100; 95% confidence interval 83–119). However, an excess of stomach cancer (18 observed vs. 9.37 expected: SMR = 192, 95% CI 114–304) was observed. There was also a tendency for higher incidence and mortality in stomach and brain cancer with increasing number of fires. There were four deaths from brain cancer compared to 0.8 expected (SMR = 496; 95% CI 135–1270) in the highest exposure category. Fire fighters are, however, not systematically exposed to known stomach or brain carcinogens, and the results need confirmation in further studies with extensive exposure evaluations. © 1994 Wiley-Liss, Inc.     

Lung function in fire fighters, I: a three year follow-up of active subjects.

From a cohort of 1,768 Boston fire fighters studied initially in 1970, pulmonary function measurements were repeated on 1, 146 active subjects in 1974. The mean time between examinations was 3.4 years. The data on 1,430 subjects after one year of follow-up had indicated excessive decrements in levels of forced vital capacity and one-second forced expiratory bolume which were related to the frequency of fire exposure. The annual decline over three years was less than that observed over one year and could not be related to the number of fires fought or to other indices of acute fire exposure. Selection factors within the fire department appear to be important in protecting fire fighter from continued loss ventilatory capacity.     

Acute effects of routine firefighting on lung function

We undertook a study to determine the acute effects of routine firefighting on lung function and the relationship between these acute effects and nonspecific airway responsiveness. For 29 firefighters from a single fire station, we calculated the concentration of methacholine aerosol that caused a 100% increase in specific airway resistance (Pc100). Over an 8-week period we than measured FEV1 and FVC in each firefighter before and after each 24-hr workshift and after every fire. From 199 individual workshifts without fires, we calculated the mean +/- 2 SD across-workshift change in FEV1 and FVC for each firefighter. Eighteen of 76 measurements obtained within 2 hr after a fire (24%) showed a greater than 2 SD fall in FEV1 and/or FVC compared to two of 199 obtained after routine workshifts without fires (1%; p less than .001). On 13 of 18 occasions when spirometry decreased significantly, we obtained repeat spirometry (postshift) 3-18.5 hr after fires, and on four of these occasions FEV1 and/or FVC were still more than 2 SD below baseline. Decrements in spirometry occurred as often in firefighters with high Pc100s as in those with low Pc100s. In two firefighters in whom FEV1 and FVC fell by more than 10% after fires, we repeated measurements of methacholine sensitivity, and it was increased over the prestudy baseline. These findings suggest that routine firefighting is associated with a high incidence of acute decrements in lung function.(ABSTRACT TRUNCATED AT 250 WORDS)     

Longitudinal decline in lung function in patients with occupational asthma due to western red cedar.

BACKGROUND: There are few reports about longitudinal changes in lung function in asthmatic patients. Patients with asthma had a greater loss of lung function than normal healthy adults. To date, there have been no studies about the longitudinal changes in lung function in patients with occupational asthma. METHODS: 280 male patients with red cedar asthma (RCA) who were followed up for at least one year were the study group. The exposed controls consisted of 399 male sawmill workers. Forced expiratory volume in one second (FEV1) was measured with a Collins water spirometer. Changes in FEV1 over time (FEV1 slope) were calculated by a two point method for each subject. Atopy was considered to be present if the subjects showed at least one positive response to three allergens by skin prick test. RESULTS: Multiple regression analysis was carried out to examine factors that might affect longitudinal decline in FEV1. Patients with RCA who were still exposed had a greater decline in FEV1 slope (-26 ml/y) than sawmill workers. Smokers also showed a greater rate of decline in FEV1 (-43 ml/y) than non-smokers. CONCLUSIONS: Patients with RCA who continued to be exposed had a greater rate of decline in FEV1 than sawmill workers. Early diagnosis of occupational asthma and removal of these patients from a specific sensitiser is important in the prevention of further deterioration of lung function and respiratory symptoms.     

Decline in lung function and mortality: the Busselton Health Study

BACKGROUND: There is a direct association between level of lung function, measured by forced expiratory volume in 1 second (FEV1) and mortality rates. A low FEV may result from an increased decline in FEV1 with age, which may be an independent predictor of mortality. OBJECTIVE: To examine the association between decline in FEV1 and mortality in a cohort from a community health study. SETTING AND METHODS: From five cross sectional studies in Busselton between 1969 and 1981 a cohort of 751 men and 940 women was identified who had three assessments of lung function over a six year period and had other health related data collected. Each subject's average FEV1 and decline in FEV1 (litre/year) were calculated from these three measurements. Mortality follow up to December 1995 was obtained. Cause of death was taken as the certified cause of death from the death certificate using ICD9 categories. RESULTS: The average decline in FEV1 was 0.04 litre per year (SD = 0.07) for men and 0.03 litre per year (SD = 0.06) for women. Average FEV1 was significantly associated with all cause and cardiovascular disease mortality in both sexes. In women there was a significant association between decline in FEV1 and death from all causes, after adjusting for average FEV1, age, smoking, coronary heart disease, and cardiovascular disease risk factors; a 0.05 litre per year increase in the rate of decline of FEV1 increased the risk of death for all causes by 1.23 (95% confidence interval 1.06, 1.44). In men the effect of decline in FEV1 on death rate was less; for all men the hazard ratio for a 0.05 litre/year greater decline in FEV1 was 1.19 (0.99, 1.21). CONCLUSION: Decline in lung function, measured by FEV1 is a predictor of death, independent of average FEV1 and risk factors for cardiovascular disease.     

Accelerated loss of lung function and alveolitis in a longitudinal study of non-smoking individuals with occupational exposure to asbestos.

Long-term asbestos workers who insulate pipes and boilers may develop interstitial lung disease associated with loss of lung function. To quantitate annual loss of lung function, 77 individuals with chest X-rays greater than or equal to 1/0 ILO category who were life-long non-smokers or ex-smokers for greater than 5 years were evaluated. Study parameters included pulmonary function tests and bronchoalveolar lavage for a mean of 3 visits over 30 +/- 2 months. The study participants were 56 +/- 1 years old and had 31 +/- 1 years' occupational exposure to asbestos. At the first visit, multiple regression analysis revealed significant associations between rales or radiographic opacities and VC, FEV1, and total lung capacity; significant associations were also found between neutrophils/ml lavage fluid with FEV1 and diffusing capacity (all p less than 0.05). Annual declines for the asbestos-exposed were VC -92 +/- 28 ml/yr and FEV1 -66 +/- 21 ml/yr. Declines in VC and FEV1 were less in those with reduced lung function at the initial visit. There were no significant associations between any of the annual declines and cells recovered by bronchoalveolar lavage. Compared to other asbestos-exposed cohorts followed longitudinally, asbestos insulators with radiographs greater than or equal to 1/0 and exposure greater than or equal to 20 years have larger rates of FVC and FEV1 decline for both non-smokers and ex-smokers.     

Domestic pollution and respiratory illness in a Himalayan village

Summer and winter surveys of a village in Ladakh have been used to study respiratory illness and domestic pollution from fires in an arid high altitude region of northern India. The prevalence of chronic cough with chronic phlegm rose steeply with age, and was greater among women than men. The percentage of villagers with a forced expiratory volume in one second/forced vital capacity (FEV1/FVC) ratio of less than 65% also rose with age, to include 24% of men and 32% of women over 50 years in the summer survey. Lung function was significantly worse in those reporting chronic cough, independently of age and sex (p less than 0.001). Carbon monoxide (CO) measurements were used to assess domestic pollution from fires. Amongst the small minority of smokers (all men) CO in exhaled air was higher than in non-smoking men. In non-smoking men and the women, levels of exhaled CO were very significantly higher in winter than in summer, as were the levels of CO measured in the houses. There was a fall in FEV1 (but not FVC) between summer and winter (p less than 0.0001), and an association was found between individual change from summer to winter in exhaled air CO and the individual change in FEV1 (p less than 0.01). A significant negative association was found between the winter value of CO in exhaled air and FEV1/FVC ratio in women (p less than 0.05), although a similar association in men was non-significant. No significant associations were found between winter pollution levels and the presence of chronic symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)     

Occupational noise exposure and hearing loss in fire fighters assigned to airport fire stations.

The National Institute for Occupational Safety and Health (NIOSH) was requested to conduct a health hazard evaluation (HHE) at a large metropolitan fire department. The request concerned the hearing levels and noise exposures of fire fighters who were assigned to two fire stations serving the international airport. There was concern that these fire fighters were at a greater risk of accruing hearing loss than fire fighters located at other fire stations because of the addition of aircraft noise to their occupational noise exposures. The city also requested that NIOSH investigate other fire stations, not influenced by the airport, for noise exposures and hearing ability among a larger population of the fire fighters. NIOSH investigators conducted noise surveys at five fire stations and examined the hearing ability of 197 fire fighters. The noise surveys consisted of personal noise dosimetry on fire fighters assigned to the fire station for the entire 24-hr tour of duty over 2 consecutive days at each of the five stations. A NIOSH investigator accompanied the fire fighters on their vehicle to log response times and activities. The audiometric examinations were pure-tone, air conduction tests administered according to the Occupational Safety and Health Administration's (OSHA's) hearing conservation amendment. The noise dosimetry results revealed time-weighted averages (TWAs) that ranged from 60 to 82 dBA. However, the levels encountered during Code 3 responses (warning lights, sirens, and air horns) reached 109 dBA for a 1-min time period. The audiometric results showed that the average fire fighter exhibited a characteristic noise-induced permanent threshold shift.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fire fighters' exposure to carbon monoxide during Australian bushfires

Fatal entrapments of Australian bushfire fighters have led to suggestions that carbon monoxide (CO) poisoning could have contributed to these accidents by impairing the fire fighters' judgement. Carboxyhemoglobin saturation (COHb%) levels were assessed from alveolar CO levels in 24 fire fighters working with handtools and in 12 accompanying scientific observers, before and after fire fighting (duration 37-187 min) on 15 experimental bushfires. Carboxyhemoglobin levels increased on average by 0.7% per hour in the fire fighters and by 0.3% per hour in the observers. Nonsmoking fire fighters had lower COHb% after fires than the smokers had before fires. Estimates of environmental CO concentrations (including cigarette smoke) during the fires averaged 31 parts per million (ppm) for the smokers, 17 ppm for the nonsmoking crew members, and 11 ppm for the observers, none of whom smoked. The highest estimates of environmental CO arising solely from bushfire smoke were 40 to 50 ppm. Smokers were exposed to as much CO from their cigarettes as from bushfire smoke. Carboxyhemoglobin levels at the end of 8-hr fire fighting shifts, predicted from these levels of environmental CO, averaged about 5% (maximum 11%) in smokers and about 3% (maximum 7%) in nonsmokers. Acute levels of COHb% of this degree are not considered to have significant effects on health or performance. These results indicate that bushfire fighters are generally unlikely to experience hazardous levels of CO exposure.     

Interaction between a heme oxygenase-1 gene promoter polymorphism and serum beta-carotene levels on 8-year lung function decline in a general population: the European Community Respiratory Health Survey (France)

Oxidative stress is thought to play a major role in the pathogenesis of chronic obstructive pulmonary disease, characterized by impaired lung function. A large number (> or =33) of GT repeats (L-allele) in the gene of the powerful antioxidant enzyme heme oxygenase-1 has been associated with susceptibility to accelerated lung function decline. In contrast, beta-carotene may help to protect against accelerated decline. To determine whether high serum levels of beta-carotene might counterbalance the greater susceptibility of L-allele carriers, the authors analyzed the annual decline in forced expiratory volume in 1 second (FEV1) in a general population sample of 523 French subjects (20-44 years, 50% men) examined in 1992 and 2000 as part of the European Community Respiratory Health Survey. Analysis of covariance, adjusted for sex as well as baseline age, body mass index, smoking, and FEV1, showed that, among subjects with low beta-carotene levels, L-allele carriers experienced a steeper mean FEV1 decline than did noncarriers (mean = -58.8, 95% confidence interval: -73.2, -44.5 vs. mean = -34.7, 95% confidence interval: -38.9, -29.8 ml/year) (p = 0.009), whereas among subjects with high beta-carotene levels, the FEV1 decline was not different in L-allele carriers and noncarriers (two-sided p = 0.9). The results suggest that high levels of beta-carotene might counterbalance the effects on FEV1 decline of a genetically determined deficiency in antioxidant response.     

Heart rates in fire fighters using light and heavy breathing equipment: similar near-maximal exertion in response to multiple work load conditions

Intense exertion is an occupational hazard inherent to fire fighting. This study was designed to look at the exertion levels that fire fighters attain during a fire fighting exercise when using (1) no self-contained breathing apparatus (SCBA), (2) light SCBA, and (3) heavy SCBA. Exertion levels were measured as a function of the heart rate increase relative to the maximum predicted heart rate determined by a standard treadmill exercise test. Five fire fighters wore electrocardiographic monitors during a routine fire fighting exercise. Heart rates increased rapidly to 70% to 80% of maximum within the first minute and then plateaued at 90% to 100% until the attack on the fire was completed. There was no significant difference between exertion levels when using no SCBA, light SCBA, and heavy SCBA (split-plot analysis of variance, p greater than .25). These results suggest that fire fighters attain an intense level of physical activity quickly and maintain that level as long as they are actively engaged in fighting fire. These results also suggest that regardless of the weight of the SCBA, if employed, fire fighters exert themselves from 85% to 100% of their maximum and adjust their work output to maintain that near-maximal level.     

The effects of a worksite health promotion program on the wives of fire fighters

One method of increasing the cost-effectiveness of worksite health promotion programs is to develop programs that also have an impact on risk factors of family members and friends of the employees. In this study, 41 wives of fire fighters were interviewed concerning changes the fire fighters and they had made in their health habits--exercise, weight, and consumption of fats, fruits/vegetables, and cereal/whole grain breads--in the previous year. Thirty-two were wives of fire fighters who had received a worksite health promotion program and nine were wives of fire fighters who had not yet received the program. Findings of our exploratory study strongly suggest that wives of fire fighters who received information were more aware of the program (93% vs 56%), had greater exposure to the written diet plan (72% vs 11%) and guide to high fat foods (72% vs 0%) than controls. Furthermore, the intervention led to changes in the fire fighters' health habits that were reported by the wives. No significant changes in the wives' health habits occurred as a result of the intervention, although the changes were in the predicted direction in every category; changes by the wives were, however, related to changes by fire fighters. Involvement of the fire fighters in the preparation of meals and sharing of information from the intervention program by the participant with the wife, were related to change in health habits of the wives.(ABSTRACT TRUNCATED AT 250 WORDS)     

Chest illnesses and the decline of FEV1 in steelworkers

This study relates the impact of various medical conditions to clinically important forced expiratory volume in 1 second (FEV1) declines in a cohort of steelworkers evaluated cross-sectionally and longitudinally. Medical records of 1171 randomly chosen steelworkers were obtained from the medical department of a steel company. We reviewed the medical records for information regarding demographic parameters, smoking status, spirometry indexes, job history, and the worker's respiratory health. These workers had performed annual spirometry from 1980 to 1991 at least once and up to 12 times. We compared the prevalence of medical conditions in 203 male never-smoking steelworkers in this group of 1171 workers by separating workers into three groups on the basis of final predicted FEV1 values (< 65%, between 65% and 79%, and > or = 80%). We also evaluated the prevalence of medical conditions and the association between these conditions and the rate of annual decline in FEV1 in 475 steelworkers who had at least three valid tests and at least 5 years separating the first and last test by multiple logistic regression analysis. Of the 475 steelworkers, 121 were categorized as rapid decliners (an annual rate of decline in FEV1 exceeding the 75th percentile of the slope distribution), whereas the remaining workers served as controls. Three of 203 and 17 of the remaining 200 in the cross-sectional survey had final predicted FEV1 values < 65% or between 65% and 79%, respectively. Among these 20 never-smokers, the accelerated rate of decline could be reasonably explained by factors independent of dust and age in all but two. In the 203 never-smokers, hay fever and trauma occurred more frequently in those with a decreased predicted FEV1. In the longitudinal study of 475 workers, the prevalence of pneumonia was significantly greater in the rapid decliners, whereas the prevalence of allergy, asthma or hay fever, and trauma approached a significant excess in number. Logistic regression models demonstrated that aging, weight gain, smoking, trauma, pneumonia, and a history of allergy, asthma, or hay fever were independently related to the risk of a clinically important decline of FEV1 in this group. In summary, there are multiple risk factors for an accelerated rate of decline in workers with dust exposure. An accurate assessment of the causes for an excessive rate of lung function decline in an individual worker within a population requires an understanding of the relationship between environmental exposures, lung function decline, and the individual worker's underlying health. In addition to the three traditionally recognized variables--age, smoking, and dust exposure--the medical conditions of trauma, pneumonia, and allergy, asthma, or hay fever were related to a clinically important decline of FEV1 in this industrial population.     

Can exposure to coalmine dust cause a severe impairment of lung function?

It is well recognised that exposure to respirable coalmine dust causes a reduction in lung function but it has not been clear whether the impairment of function is sufficient to cause disability, unless progressive massive fibrosis occurs. From a study of 4059 men without progressive massive fibrosis who worked in the coal industry for at least ten years from the 1950s, and who were followed up and re-examined medically more than 20 years later, a subgroup was selected using criteria intended to favour those who may have suffered greater than average effects of dust exposure. These 199 men had left the coal industry before normal retiral age, had taken other jobs, and had reported symptoms of chronic bronchitis at follow up. The inverse relation between dust exposure and FEV1 among these 199 men was much more severe than the average effects previously shown among more representative groups of coalminers. The effect of exposure to respirable dust was estimated conservatively as an impairment of about 2 ml FEV1 per unit of dust exposure (gh/m3). The estimated effect among ex-smokers was more severe. These compare with a previous estimate, based on a less selected population, of 0.6 ml FEV1 per gh/m3. The new estimate in this group of 199 men corresponds to an average loss of 600 ml FEV1 in response to a moderately high dust exposure to 300 gh/m3, with correspondingly higher losses in the ex-smokers. These findings show that among a group of men intentionally selected to include those who may have suffered greater than average effects of dust exposure, the relation between exposure and FEV1 is consistent with the view that in some men even moderately high exposure to dust causes severe impairment of lung function.     

Can exposure to coalmine dust cause a severe impairment of lung function?

It is well recognised that exposure to respirable coalmine dust causes a reduction in lung function but it has not been clear whether the impairment of function is sufficient to cause disability, unless progressive massive fibrosis occurs. From a study of 4059 men without progressive massive fibrosis who worked in the coal industry for at least ten years from the 1950s, and who were followed up and re-examined medically more than 20 years later, a subgroup was selected using criteria intended to favour those who may have suffered greater than average effects of dust exposure. These 199 men had left the coal industry before normal retiral age, had taken other jobs, and had reported symptoms of chronic bronchitis at follow up. The inverse relation between dust exposure and FEV1 among these 199 men was much more severe than the average effects previously shown among more representative groups of coalminers. The effect of exposure to respirable dust was estimated conservatively as an impairment of about 2 ml FEV1 per unit of dust exposure (gh/m3). The estimated effect among ex-smokers was more severe. These compare with a previous estimate, based on a less selected population, of 0.6 ml FEV1 per gh/m3. The new estimate in this group of 199 men corresponds to an average loss of 600 ml FEV1 in response to a moderately high dust exposure to 300 gh/m3, with correspondingly higher losses in the ex-smokers. These findings show that among a group of men intentionally selected to include those who may have suffered greater than average effects of dust exposure, the relation between exposure and FEV1 is consistent with the view that in some men even moderately high exposure to dust causes severe impairment of lung function.     

Relation between dust exposure and lung function in miners and ex-miners.

A sample of men working in the British coal industry in the 1950s has been followed up and examined 22 years later. The relations between lung function and individual cumulative exposure to respirable dust have been studied in 1867 men who were still working in the industry at the time of follow up and 2192 men who had left. Levels of forced expired volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio at follow up were found to be inversely related to exposure to respirable dust after allowing for other factors, even in men without pneumoconiosis. The magnitude of this estimated effect was equivalent to a loss of 228 ml FEV1 in response to an exposure of 300 gh/m3, a moderately high exposure for this group. Ex-miners aged under 65 had worse lung function than miners on average, suggesting that ill health had encouraged some of these men to leave the industry. Whereas a more severe response to dust exposure among ex-miners under 65 was suggested, this difference could easily have arisen by chance. The presence of symptoms of chronic bronchitis was associated with reduced levels of lung function, however, and, additionally, ex-miners under 65 with chronic bronchitis showed a more severe response of the FVC to dust exposure than miners without these symptoms. Among these ex-miners with chronic bronchitis a small group of men who had taken other jobs showed a much more severe effect of dust exposure on their lung function than the average, likely in heavily exposed men to contribute importantly to disability. Men in this group who had given up smoking showed and even more severe effect of dust exposure, equivalent to a loss of 940 ml FEV1 in response to an exposure of 300 gh/m3. These results indicate that exposure to respirable dust can occasionally cause severe respiratory impairment in the absence of progressive massive fibrosis. Dust exposure was related to a parallel reduction of FEV1 and FVC, implying that the pathology of dust induced lung damage differs form that induced by smoking. This pattern of abnormality was shown by some non-smokers, whereas smokers and ex-smokers apparently severely affected by dust showed a classic obstructive pattern of abnormality with pronounced reduction of the FEV1/FVC ratio.     

Relation between dust exposure and lung function in miners and ex-miners

A sample of men working in the British coal industry in the 1950s has been followed up and examined 22 years later. The relations between lung function and individual cumulative exposure to respirable dust have been studied in 1867 men who were still working in the industry at the time of follow up and 2192 men who had left. Levels of forced expired volume in one second (FEV1), forced vital capacity (FVC), and FEV1/FVC ratio at follow up were found to be inversely related to exposure to respirable dust after allowing for other factors, even in men without pneumoconiosis. The magnitude of this estimated effect was equivalent to a loss of 228 ml FEV1 in response to an exposure of 300 gh/m3, a moderately high exposure for this group. Ex-miners aged under 65 had worse lung function than miners on average, suggesting that ill health had encouraged some of these men to leave the industry. Whereas a more severe response to dust exposure among ex-miners under 65 was suggested, this difference could easily have arisen by chance. The presence of symptoms of chronic bronchitis was associated with reduced levels of lung function, however, and, additionally, ex-miners under 65 with chronic bronchitis showed a more severe response of the FVC to dust exposure than miners without these symptoms. Among these ex-miners with chronic bronchitis a small group of men who had taken other jobs showed a much more severe effect of dust exposure on their lung function than the average, likely in heavily exposed men to contribute importantly to disability. Men in this group who had given up smoking showed and even more severe effect of dust exposure, equivalent to a loss of 940 ml FEV1 in response to an exposure of 300 gh/m3. These results indicate that exposure to respirable dust can occasionally cause severe respiratory impairment in the absence of progressive massive fibrosis. Dust exposure was related to a parallel reduction of FEV1 and FVC, implying that the pathology of dust induced lung damage differs form that induced by smoking. This pattern of abnormality was shown by some non-smokers, whereas smokers and ex-smokers apparently severely affected by dust showed a classic obstructive pattern of abnormality with pronounced reduction of the FEV1/FVC ratio.     

Pulmonary function in relation to cigarette smoking and smoking cessation. MRFIT Research Group.

BACKGROUND. More than half of the subjects in the MRFIT smoked at baseline and 10% of the subjects stopped smoking permanently during the first year of the trial. In this report, rates of decline in forced expiratory volume in 1 sec (FEV1) are compared for early permanent quitters and smokers who continued to smoke throughout the trial. METHODS. Since pulmonary function testing was not standardized across all centers until the third annual visit cycle, change in FEV1 is examined over the latter half of the trial; the level of FEV1 is analyzed cross-sectionally at the midpoint of the trial. Analyses are limited to 4,926 subjects who never used beta-blockers or smoked cigars, cigarillos, or pipes during the trial and who had annual FEV1s measured over 2-4 years in the latter half of the trial. RESULTS. Quitters during the first 12 months experienced smaller declines in FEV1 over the latter half of the trial than continuing smokers, with -50.7 ml/year versus -59.0 ml/year, respectively, adjusted for the level of FEV1 (P = 0.05). Cross-sectionally, those who had never smoked, former smokers, quitters, and continuing smokers showed a gradient of decreasing FEV1, and all four smoking groups were significantly different from each other (P less than 0.05). CONCLUSIONS. These data suggest that if a middle-aged, healthy smoker stopped smoking permanently, he could expect his FEV1 to deteriorate at a more gradual rate 3-4 years after stopping smoking than a similar smoker who continued to smoke. No information was available for the complete MRFIT cohort on the pulmonary function effects immediately following smoking cessation.     

Occupational exposures in California wildland fire fighting.

Industrial hygiene measurement of exposures to wildland fire fighters was conducted in northern California during three consecutive fire seasons (1986-1989) in conjunction with three separate health effects studies. Chemicals that were monitored included carbon monoxide, total and respirable particulates, polyaromatic hydrocarbons (PAHs), crystalline silica, aldehydes, and benzene. Measurements were taken at both wildland fires and prescribed (planned) burns. A variety of collection methods were employed--colorimetric detector tubes and a CO monitor were used for direct-reading area measurements; colorimetric diffusion tubes, filter cassettes, sorbent tubes, and passive vapor monitors were used for determining personal time-weighted average exposures. A new screening method (National Institute for Occupational Safety and Health Method 2539) was used to identify the presence of specific aldehydes. Results show that wildland fire fighters may at times be exposed to concentrations of carbon monoxide, total or respirable particulates, or silica at levels near or higher than recommended occupational exposure limits, although group means were generally well below the limits. Time-weighted average formaldehyde levels, measured in a few instances above 0.37 mg/m3 (0.3 ppm), indicate a potential for formaldehyde-induced eye or respiratory irritation under these conditions. Certain characteristics of the work such as high altitude, temperature, and breathing rate; extended work shifts; and additional off-shift exposures suggest that adjustment of 8-hr exposure limits may be necessary to provide adequate protection. In part, because of the rigors of performing industrial hygiene measurements under fire fighting conditions, data are limited and could not be considered representative of the full range of exposures fire fighters may encounter.(ABSTRACT TRUNCATED AT 250 WORDS)     

Congenital anomalies among the offspring of fire fighters

A case-control study has been conducted to determine the association between employment as a fire fighter and congenital heart defects among the offspring. Cases were fathers of all children born between 1979 and 1986 in Ontario, Canada, who were diagnosed with a cardiac congenital anomaly during the first year of life (n = 9340). Matched controls (n = 9340), defined as fathers whose child did not have a congenital anomaly, were randomly selected from the Ontario birth certificate file. In order to identify those fathers who had been employed as a fire fighter, the cases and controls were linked to a cohort of Metropolitan Toronto fire fighters. Eleven cases and nine controls worked as fire fighters, giving an odds ratio of 1.22 (95 percent confidence interval 0.46–3.33). This study had sufficient power to detect the level of risk reported in one previous study; however, these results do not support a hypothesis of elevated risk of cardiac congenital anomalies among the offspring of fire fighters. © 1996 Wiley-Liss, Inc.