Evaluation of specific occupational asthma risks in a community-based study with special reference to single and multiple exposures

OBJECTIVES: To compare two job exposure matrices (JEMs) for the evaluation of asthma risks related to specific occupational exposures in a community-based study. METHODS: A questionnaire on self-reported asthma, respiratory symptoms and current occupation was sent to the participants of the European Community Respiratory Health Survey in five areas in Spain. Both an asthma-specific JEM, including expert judgment steps and a general JEM, were applied to occupational codes. Risks of current asthma symptoms and wheeze in the last year associated with the obtained exposure estimates were evaluated. Correlations between specific exposures were investigated using explanatory factor analysis. RESULTS: Occupational exposures to the high-molecular-weight (MW) agents flour dust, enzymes, mites and animal-derived proteins as obtained by the asthma-specific JEM were positively associated with asthma outcomes. The effect of additional expert judgment steps was limited. High exposures to biological dust assessed by the general JEM without expert judgment was also associated with asthma. Many of the exposed individuals worked in environments with multiple exposures. CONCLUSIONS: Asthma risks associated with occupational exposures to specific high-MW agents could be identified from a population-based study using an asthma-specific JEM. Application of JEMs can be a useful tool to estimate asthma risks attributable to specific occupational exposures in the general population. However, these specific exposure risks should be interpreted in connection with the whole of concomitant exposures constituting the work environment.     

挡车女工听力与视力的职业危害

纺织行业挡车女工长期受到噪声、棉尘、湿热等多种职业危害。本文重点对噪声危害和精细作业引起挡车女工的视力减退进行了调查 ,结果报道如下。1　对象与方法1.1　布机挡车工 140名 ,均为女性 ,年龄 19岁～ 4 8岁 ,平均 32 .5岁 ;工龄 3年～ 2 5年 ,平均 11.4年。选择同行业从事其他工作 ,年龄和工龄与此相匹配的 16 7名女工作对照。1.2　使用ＮＤ2 精密声级计和ＳＴ— 80型数字式照度计测定噪声和照度 (仪器经国家计量院校准 ) ,噪声和照度监测采用网格式布点。1.3　用丹麦产ＡＳ— 72型听力计检查双耳听力 ,每耳查 50 0、1Ｋ、2ＫＨＺ三个…     

Evaluation of zinc protoporphyrin in an occupational environment.

Zinc protoporphyrin (ZnP) has been identified by several investigators as the predominant fluorescent porphyrin accumulating in erythrocytes as a result of chronic lead absorption or iron deficiency anemia. This report describes an evaluation of a new portable hematofluorometer for the determination of ZnP in finer puncture or venous blood samples. Samples were obtained from a number of employees in various job categories at steel operations throughout the United States to study the utility of ZnP as a biologic monitoring method in the occupational environment. Urinary lead, urinary aminolevulinic acid and blood lead were also determined on the same employees to examine any relationships among these measurers and to estimate a biologic threshold limit value for ZnP. The results of this investigation show that there is little elevation of the ZnP level with increasing blood level until the blood lead concentration reaches the area of 50--60 micrograms/dl. A biologic threshold level of 300 micrograms/dL, which correlates with a blood level of 60 micrograms/dL, is suggested as a guideline value for identifying workers requiring further investigation.     

Evaluation of occupational exposure to aromatic polycyclic hydrocarbons in bituminous pulp plants]

A method was developed for isolation of aromatic polycyclic hydrocarbons (APH) from atmospheric air. Air samples were filtered through Whatman GF/C filter papers, subsequently extracted with benzene. Aromatic polycyclic hydrocarbons were isolated from the extract, purified by column chromatography on aluminium oxide and determined by gas chromatography. This method was applied to determine qualitatively and quantitatively: naphthalene, anthracene, pyrene, perilene, biphenyl, fluoranthene, phenanthrene, benzo(a)pyrene, dibenzo(a,c)anthracene, dibenzo(g,h)anthracene, 11H-benzo(a)fluorane, 11H-benzo(b)fliorene, benzo(g,h,i)perylene, benzo(a)anthracene, chrysene, indene and durene. Professional exposure in years 1977-1989 was comparatively assessed using the evaluation criterion for APH expressed as the benzene fraction (0.2 mg/m3--USA standard) and as benzo(a)pyrene (0.00015 mg/m3--USSR standard). According to the accepted standards, working conditions in the examined plants entail a risk for the employees. Comparison of the results obtained before and after reconditioning of the machinery suggests the need for further modernization aimed at application of new technical solutions allowing for limitation of pollutant emission to air.     

两种测量方法评价稳态噪声暴露与高频听力损伤的剂量-反应关系

目的 比较环境噪声水平、个体噪声暴露和累积噪声暴露量评价稳 态噪声所致听力损伤剂量－反应关系的优劣。方法 用个体计量仪采集8小时工作期间挡车工的噪声暴露数据,并将数据传输至微机存储和分析。选择细砂、布机车间使用不同类型机器的4组工人作为观察对象,每组选择3－5人,分别在早、中、晚班各测量1个班次的个体噪声暴露数据;用网格法和普通声级计测量每组工人工作环境的噪声水平,同时对该纺织厂接触稳态噪声的163名工人进行了问卷和听力检查。结果 经年龄、性别校正后的高频听力损伤患病率为64．4％;语频听力损伤患病率为2．5％,其中高频听力损伤患病率随噪声暴露的剂量增大而升高,呈现典型的剂量－反应关系。经趋势卡方检验和和Logistic回归模型拟合,累积噪声暴露量评价剂量－反应关系的效果优于噪声级,个体噪声暴露的效果优于环境噪声水平。结论 个体噪声暴露和累积噪声暴露量是评价稳态噪声暴露与高频听力损伤剂量－反应关系最好的暴露评价指标。     

Arterial hypertension in workers exposed to occupational noise

A study was carried out in three groups of workers of comparable anthropometric characteristics who were exposed to various levels of noise at the workplace. Among the workers from the textile industry (a jute weaving mill) who worked in exposure to the noise intensity of 90-102 dB the prevalence of arterial hypertension was much higher than in those who were exposed to the noise levels within permissible limits.     

Evaluation of occupational exposure to mixed dusts and polycyclic aromatic hydrocarbons in silicon carbide plants

Workers in the silicon carbide industry have experienced occupational health diseases, particularly lung disorders such as silicosis. The silicon carbide production process mainly employs petroleum coke, sawdust, pure crystalline silica and graphite. Since crystalline silica is present in the occupational environment, the airborne dust content of various polymorphs of silica, especially quartz, cristobalite and tridymite, was determined by X-ray diffraction analysis. The analytical method was modified to eliminate graphite, since it overlaps with the main diffraction plane of quartz. Exploratory field surveys were conducted to identify the minerals present in that occupational environment and to evaluate the validity of the analytical method. The surveys provided information on the mineralogical nature of the dust, its respirable content and the concentration of silica polymorphs. Polycyclic aromatic hydrocarbons also were measured, and the effect of their adsorption on graphite was evaluated.     

Effects of a hyperbaric environment on human brain stem function with specific reference to auditory brain stem responses

Hyperbaric chamber dives at 31 ATA with helium-oxygen were performed at the Japan Marine Science and Technology Center in 1987. During simulated underwater experiments, auditory brain stem responses were recorded in 4 professional divers for assessment of brain stem function. All divers had no clinical symptoms at 150 m below sea level, and their ABRs also showed no significant changes. During the 150-250 m depth saturation dives, all divers complained of various symptoms such as euphoria, ataxia, joint pain, tremor and dyspnea, while, I-III and I-V interpeak latencies on their ABRs increased with a tendency of recovery. Furthermore, the changes of both interpeak latency were independent of each other. These results indicate that transient dysfunction clinically or subclinically occurred at the processes between 150-300 m below sea level. Moreover, independent changes of I-III and I-V interpeak latencies in this study may mean that the pathways reached to the generation sites of wave III and V were different.     

The ovulation method in developing countries with special reference to India

Time may prove that no equal exists to natural family planning (NFP) methods in regard to safe and wide applicability without much sacrifice of reliability, especially in developing countries because of its inexpensiveness and dependence on the couple rather than doctors or paramedical staff. In India, for example, the vast majority of Indians, regardless of caste of religion, are indoctrinated to practice abstinence of various kinds: fasting for either religious or social reasons, abstinence from sleep, abstinence from speech, sexual abstinence during Ramzan (Muslims) and Adimasam (South Indians). With this background, there is great scope for wider use of the Ovulation-Method (Billings). NFP helps in the establishment of a "self-energized family," which is the aim of community health workers in developing countries. A World Health Organization (WHO) study conducted in India, Philippines, and El Salvador revealed some salient findings: the days of menstruation were only 4.4 days (5.6 days in developed countries); and the fertile period, defined as days of sticky mucus plus slippery mucus (3 days), averaged 8 days (10.6 days in developed countries). In 149 women there was only 1 day of mucus before the peak day (PD); there were 2 days of mucus in 479 women (7%); and there were days of mucus in 649 (10%). Illiteracy, poverty, and marital problems were encountered in many couples. Continuation rates were significantly high in the WHO study (1979) and the Karnataka State Study (1981). Friction caused by abstinence was experienced by only 1.7-4.6% of husbands in the Karnataka Study of 2790 couples with detailed records on this aspect. In developing countries where the dignity of a woman needs to be raised, an educational method that lends itself to the integrated teaching of health, hygiene, and nutrition concepts and practices is appealing. The responsible behavior of the husband together with the wife's effort in recording her fertility creates a marital partnership with the woman sharing on an equal basis with her husband.     

纺织厂挡车工个体噪声暴露测量的评价

目的比较个体计量仪与声级计评价挡车工噪声暴露的异同。方法用个体计量仪采集一工作日内挡车工的噪声暴露动态资料并将数据传输至微机存储和分析。选择前纺、细纱、布机车间使用不同类型机器的6组挡车工作为观察对象,每组3～5人,分别在早、中、晚班各测量1个班次的个体噪声暴露数据。同时采用网格法和普通声级计测量噪声水平。结果个体计量仪测定结果显示,挡车工在一个工作日内噪声暴露的水平是稳定的：对同一组档车工的测量结果表明,挡车工个体间噪声暴露水平的变异大于不同工作日之间的变异。个体计量仪测量的噪声暴露水平等于或高于声级计测量的结果,最大可达4．6dB（A）。结论噪声个体计量仪可以连续动态记录挡车工的实际噪声暴露,其结果高于或等于声级计定点测量结果。在今后噪声暴露评价时应考虑采用这种测量方法。