摘要:

AbstractThis study compares the pulmonary function and prevalence of respiratory symptoms and disorders among school children living in smelter towns and other communities of Arizona. The rate of asthma was found to be significantly higher in whites than Mexican‐Americans, although differences in related problems, such as wheezing, were not significant. When the subjects were grouped by area of residence, the children living in areas with relatively high particulate levels had significantly lower pulmonary function than children living in areas with low particulate levels. No relation between symptoms or pulmonary function and sulfur dioxide levels was observe

ISSN:0271-3586    

DOI:10.1002/ajim.4700010312

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractMortality for three groups of ICD codes covering acute, chronic, and malignant respiratory diseases were studied for adult white women in communities near or adjacent to primary copper smelting facilities in the United States between 1968 and 1975, a period when women had not as yet entered the industrial work force.A previous comprehensive survey, sponsored by the EPA, of all U.S. counties used multiple regression analysis as a method of statistical surveillance to assess the association of mortality with industrial activity. This preliminary study suggested an excess mortality from non‐malignant respiratory diseases in copper mining and smelting counties. We directly examined town mortality rates for white female residents, aged 35 to 74, in eight U.S. copper smelting communities and compared them to demographically and geographically matched communities without industries likely to produce significant air pollution, using death certificates obtained from state sources. Site‐specific air quality data were also obtained for these communities.Our direct examination of community death rates for copper smelting towns confirmed the preliminary observation at the county level of an excess risk from acute respiratory diseases but did not detect evidence of an elevatedmortality from chronic respiratory diseases or cancer of the respiratory tr

ISSN:0271-3586    

DOI:10.1002/ajim.4700010313

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractSubmicrometer H2SO4droplets can affect pulmonary functions in humans. The lowest concentration which has been reported to produce a statistically significant effect on pulmonary mechanics is l mg/m3. Effects on tracheobronchial mucociliary clearance of inert particles were observed in our laboratory at much lower concentrations. For ten nonsmoking humans exposed for one hour via nasal mask to 0.1 mg/m3of H2SO4, the mean bronchial clearance half‐time was reduced by 38% (p<0.02) while for l mg/m3, it was increased by 48% (p<0.03). Four donkeys exposed for l hour daily to 0.1 mg/m3six months developed clearance abnormalities which persisted for at least three months after the last exposure. The patterns of mucociliary clearance responses to H2SO4are similar to those seen previously in humans and donkeys following exposure to cigarette smoke, a known causal factor for chronic bronchiti

ISSN:0271-3586    

DOI:10.1002/ajim.4700010314

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe effects of a four‐hour exposure (via a Plexiglas hood) to sulfur dioxide (SO2) on airway reactivity was studied in both normal and allergic conscious sheep. Allergic sheep were defined as animals in whom inhalation ofAscaris suumextract resulted in an increase in mean pulmonary flow resistance (RL). Airway reactivity (δRL) was assessed by measuring the increase in RLafter 18 breaths of 0.25% carbachol, from an initial value obtained after 18 breaths of buffered saline. RLand δRLwere determined prior to, immediately after and 24 hours following SO2exposure in three groups of sheep: six normal sheep exposed to 5 ppm SO2(group A); six normal sheep exposed to 10 ppm SO2(group B) and seven allergic sheep exposed to 5 ppm SO2(group C). RLwas not affected by SO2exposure in any group but both groups B and C showed increases in δRL24 hours after exposure. Since the increase in δRLwas greater in group C than in either groups A or B, we conclude that allergic sheep have enhanced susceptibility to the injurious airway effects o

ISSN:0271-3586    

DOI:10.1002/ajim.4700010315

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe results of cross‐sectional clinical field surveys of 45 cable manufacturing workers and 90 telephone cable splicers are presented. Despite the rare occurrence of clinically overt lead poisoning among these occupational groups, high prevalence of lead‐associated central nervous system symptoms and gastrointestinal symptoms was found. Hierarchical log‐linear models for multidimensional contingency tables were fitted to those data and indicate that there is a partial correlation between reported symptoms and zinc protoporphyrin: individuals with high zinc protoporphyrin levels were more likely to report symptoms than those with low levels. No significant partial association was found between symptoms and blood lead. Because of the intermittent lead exposure encountered in one of the populations, individuals were identified with “normal” blood lead levels associated with “elevated” zinc protoporphyrin concentrations, thus indicating the difference in the biological significance between indicators of lead absorption (blood lead) and of biological response tests (ZPP). Suggestion is made that both types of diagnostic tests be utilized in the medical surveillance of lead‐

ISSN:0271-3586    

DOI:10.1002/ajim.4700010316

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

ISSN:0271-3586    

DOI:10.1002/ajim.4700010317

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractPotential kidney function decrement with long term lead exposure is important in the overall assessment of adverse health effects of lead in industrial workers or other exposed groups. Two clinical field studies of secondary lead smelter workers have shown that a significant proportion of workers had slightly to moderately elevated blood urea nitrogen (BUN) and creatinine levels; the prevalence was higher in those with longer lead exposure. Since a decrement of kidney function with age has been documented, and since duration of lead exposure may also be strongly related to age, it was necessary to assess the age dependent renal function decrement in control (non‐lead‐exposed) populations. BUN and creatinine levels in the lead exposed workers showed a much more significant correlation with age than that which was found in the non‐exposed populations; the correlation remained statistically significant after correcting for the age‐dependent decrement derived from the control populations. Moreover, highly significant correlations between BUN and creatinine and the biological indicator of lead absorption, zinc protoporphyrin, were found. The results indicate a sizeable and significant decrement in kidney function in the secondary lead smelter workers studied; by removing its age‐dependency, this effect was found to be lead‐induced. In other occupational groups, with lesser and/or shorter lead exposure, a significant effect on renal function as reflected in BUN and creatinine levels could not

ISSN:0271-3586    

DOI:10.1002/ajim.4700010318

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractIt has been shown that subclinical impairment of the peripheral nerves may occur in neurologically symptom‐free lead workers. In a cross‐sectional study, 78 workers from two storage battery plants and one engineering shop were studied; their lead exposure had been monitored with regular blood lead measurements (PbB). The reference group comprised 34 unexposed manual workers. An exposure‐effect relationship between occupational lead exposure and nerve functions emerged, as nerve conduction velocities decreased with increasing PbBs. The strongest correlations were found between PbB measures and sensory and motor conduction velocities of the median nerve. An exposure‐response relationship also emerged as the proportion of subjects with abnormal nerves increased with increasing exposure levels.In a prospective study 24 workers were followed‐up from the commencement of their lead work for one year and 16 for two years. The lead exposed showed a tendency of decreasing conduction velocities of arm nerves, but as a group they did not differ statistically significantly from the control group. When the lead exposed were divided into two groups using the median PbBs as the splitting point, the ones with PbBs over 30 μg/100 ml showed slowing of several nerve conduction velocities, while in the lower exposure the conduction velocities remained at the initial level. Again the clearest difference was noted in conduction velocities of the median nerve.Nerve conduction velocities, especially in the arm nerves slow down in lead exposure and this impairment is caused by really low lead exposure as noted in the prospective follow‐up study, which can be regarded as interv

ISSN:0271-3586    

DOI:10.1002/ajim.4700010319

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe association between lead absorption and objective psychological performance tests in five groups with different levels of lead absorption was studied in the following groups: (1) a control, non‐lead‐exposed group; (2) cable splicers, (3) cable manufacturers, and (4) secondary lead smelter workers. The following performance tests were used: Block Design, Digit Symbol, and Embedded Figures. Age‐corrected performance test scores and the average of three test scores (INDEX) were used throughout. A significant association between performance tests scores and increased lead absorption was found. Zinc protoporphyrin level was a more “powerful” (in the statistical sense) indicator of lead‐induced CNS effects than blood lead levels. This study provides additional evidence that neurotoxic effects associated with occupational exposure to lead can be demonstrated by means of performance tests. It has been known and widely accepted that increased lead absorption is associated with “non‐specific” subjective symptoms: tiredness, sleep disturbance, irritability, etc. Psychometric techniques (including an appropriate statistical analysis strategy) are highly sensitive for the early detection of CNS neurotoxicity, such as metal toxicity. Moreover, even in lead‐exposed but asymptomatic individuals, a significant correlation (negative) between test scores and levels of lead absorption could be detected. It is concluded that workers exposed to lead at levels considered “safe” might be at risk of developing brain dysfunction

ISSN:0271-3586    

DOI:10.1002/ajim.4700010320

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe toxicology of sulfur oxides is discussed briefly. The effects of sulfur dioxide (SO2) are largely confined to the upper airways except during exercise or if the gas is taken up by a carrier aerosol. SO2may be adsorbed as a monomolecular layer on dry particles, such as elemental carbon, or dissolved in aqueous droplets. Hydrated SO2forms bisulfite and sulfite ions, which are rapidly oxidized (detoxified) by sulfite oxidase, an enzyme, to form sulfate. SO2in carrier aerosols (dry or aqueous solutions) may be oxidized to sulfuric acid. The mixture of SO2(1 ppm) and a droplet of sodium chloride (1 mg/m3) has been shown to be synergistic in guinea pigs. In healthy adults, the same gas‐aerosol mixture caused no functional lung changes at rest (two separate studies), but did cause significant changes following moderate exercise. Shortness of breath and wheezing were experienced by about half of the subject

ISSN:0271-3586    

DOI:10.1002/ajim.4700010321

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY