Cord serum immunoglobulin E related to the environmental contamination of human placentas with organochlorine compounds.
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Allergic diseases are on the rise in both prevalence and severity, especially in industrialized countries. The process of allergic sensitization needs an understanding of the role environmental factors play in its development. In addition to traditionally considered air pollutants, various persistent organochlorine pollutants, which accumulate in the human body over a lifetime via food intake, are toxic in humans. Placental contamination by chemicals may act as a biologic marker for the exposure of the mother or for the fetus via transplacental transfer. Placentas were collected from term deliveries in two Slovak regions. The samples were then analyzed for 21 selected organochlorine compounds. Specimens of cord blood from 2,050 neonates were gathered for the determination of levels of total immunoglobulin E (IgE). The regions were chosen according to their environmental characteristics: a city polluted with organic chemical industry versus a rural region devoid of industrial sources of pollution. In addition, data regarding the incidence rate of atopic eczema cases in the regions were considered. Comparisons between regions revealed that both the placental contamination with 16 of 21 organochlorine compounds and the cord serum IgE levels were significantly higher in the industrial region. The findings pointed to an association between organochlorine compounds and the higher levels of total IgE in newborns, signaling a higher allergic sensitization in the industrial region. This association was supported by the higher incidence rate of atopic eczema cases in the population registered in the industrial region. (+info)
Follow-up screening of lead-poisoned children near an auto battery recycling plant, Haina, Dominican Republic.
(42/1312)
In August 1997 we performed a follow-up survey of 146 lead-poisoned children from a community near a previously active auto battery recycling smelter in Haina near Santo Domingo, Dominican Republic. Our follow-up survey confirmed a severe incidence of elevated blood lead (BPb) and erythrocyte protoporphyrin/zinc protoporphyrin (EP-ZnPP) levels. The mean BPb level was 32 micrograms/dL and the mean EP-ZnPP level was 128 micrograms/dL. The frequency distribution of BPb showed that only 9% of the children had BPb levels below the currently acceptable 10 micrograms/dL threshold level, 23% had between 10 and 19 micrograms/dL, 40% had between 20 and 39 micrograms/dL, 27% had between 40 and 99 micrograms/dL, and the remainder had > 100 micrograms/dL. These findings are significantly greater than the mean BPb and EP-ZnPP levels of 14 and 35 micrograms/dL, respectively, in a comparison group of 63 children in Barsequillo, 4 miles away. BPb frequency distributions for these groups were < 10 micrograms/dL (42%), 10-19 micrograms/dL (32%), and 20-39 micrograms/dL (16%); in the remaining 10%, BPb levels were between 40 and 99 micrograms/dL. Similarly, the corresponding frequency distribution of EP-ZnPP levels in Haina children were proportional to the severity of lead poisoning and significantly higher than those of the Barsequillo comparison group. This study reveals that at least 28% of Haina children require immediate treatment; of these, 5% with lead levels > 70 micrograms/dL are also at risk for severe neurologic sequelae, and urgent action is imperative. (+info)
Environmental pollution and human exposure to polycyclic aromatic hydrocarbons in the east Baltic region.
(43/1312)
Environmental contamination by polycyclic aromatic hydrocarbons (PAH) and human exposure were surveyed in the east Baltic region. Polluted and heavily industrialized areas are upper Silesia in Poland, northern Bohemia in the Czech Republic, and the northeast part of Estonia. In Estonia the pollution is in a defined geographic area, where lung cancer incidence is higher than elsewhere. In Silesia, exposure of some 5 million people appears to be elevated; DNA (deoxyribonucleic acid) adduct levels in white blood cells are increased in groups of residents with apparently only environmental exposure. By extrapolation, some 150 annual lung cancer cases could be predicted due to PAH in Silesia. Air levels of benzo[a]pyrene were increased in northern Bohemia, and domestic heating and power plants using brown coal appeared to be major contributors to particulate air pollution in winter. Further studies are needed to assess health risks of PAH exposure in central and eastern Europe. (+info)
Assessment of workers' exposure to aromatic hydrocarbons in a paint industry.
(44/1312)
A factory survey was conducted in a paint industry in Tehran-Iran. The time-weighted average of toluene and xylene concentration in breathing zone and environmental air were monitored by charcoal tube samplers and GC-FID. The results showed that the tank cleaners had the highest exposure to toluene and xylene (1.5-5.4 times of TLV), while the workers in packaging workshops had the lowest. However, environmental concentration did not show significant differences in workshops and their levels were all lower than the TLV. (+info)
Comparison of four peak spinal loading exposure measurement methods and their association with low-back pain.
(45/1312)
OBJECTIVES: This paper examines the performance of 4 different methods of estimating peak spinal loading and their relationship with the reporting of low-back pain. METHODS: The data used for this comparison was a subset of subjects from a case-referent study of low-back-pain reporting in the automotive industry, in which 130 random referents and 105 cases (or job-matched proxies) were studied. The peak load on the lumbar spine was determined using a biomechanical model with model inputs coming from a detailed self-report questionnaire, a task-based check list, a video digitization method, and a posture and load sampling technique. RESULTS: The methods were directly comparable through a common metric of newtons or newton meters of spinal loading in compression, shear, or moment modes. All the methods showed significant and substantial associations with low-back pain in all modes (odds ratios 1.6-2.3). The intraclass correlation coefficients (ICC) showed strong similarities between the checklist and video digitized techniques (ICC 0.84-0.91), moderate similarities between these techniques and the work sampling method (ICC 0.49-0.52), and poor correlations (ICC 0.16-0.40) between the self-report questionnaire and the observer recorded measures. CONCLUSIONS: While all the methods detected significant odds ratios, they cannot all be used interchangeably for risk assessment at the individual level. Peak spinal compression, moment, and shear are important risk factors for low-back pain reporting, no matter which measurement method is used. Questionnaires can be used for large-scale studies. At the individual level a task-based checklist provides biomechanical model inputs at lower cost and equal performance compared with the criterion video digitization system. (+info)
Exhaled nitric oxide among pulpmill workers reporting gassing incidents involving ozone and chlorine dioxide.
(46/1312)
The aim of the study was to investigate whether measurement of nitric oxide in exhaled air could be used for assessing the effects of irritants on the respiratory system, in this case recurrent ozone gassing in an occupational setting. The study population comprised bleachery workers (n=56) from a Swedish pulpmill carrying out ozone-based pulp bleaching since 1992 and controls (n=39). Both groups were investigated by measuring NO in exhaled air, methacholine challenge test and answers to a questionnaire concerning history of respiratory symptoms and accidental exposure to ozone peaks. There was no significant difference in NO output between exposed subjects and controls (median 67.2 versus 55.0 nL x min(-1), p=0.64). However, among bleachery workers reporting ozone gassings, the median NO output was 90.0 nL x min(-1) compared to 58.8 nL x min(-1) among those not reporting such incidents (p=0.019). There was no relation between exhaled NO and the prevalence of respiratory symptoms or bronchial hyperresponsiveness. In a multiple regression model, only reported ozone gassings were associated (p=0.016) with NO output. The results indicate an association between previous response to ozone gassing and nitric oxide output. The increased nitric oxide output among the bleachery workers reporting peak ozone exposure may indicate that chronic airway inflammation is present. Further studies are needed to evaluate the extent to which nitric oxide can be used for biological monitoring of respiratory health effects, and to relate it to other markers of airway inflammation. (+info)
Measurements of the effectiveness of dust control on cut-off saws used in the construction industry.
(47/1312)
Materials used in the construction industry frequently contain large quantities of silica. When they are cut or shaped with power tools considerable respirable dust can be produced. Three dust control systems for use with cut-off saws have been evaluated on site: wet dust suppression using mains water, the same system using water from a portable water tank, and local exhaust ventilation. The efficiency of water suppression on cut-off saws has been precisely quantified in controlled laboratory conditions by means of measurements with and without dust control. When dust control was used on-site, the mean concentrations of airborne silica were reduced by a factor of between three and seven, the accuracy being limited by the relatively high limit of detection for silica. All controls systems generally reduced respirable dust levels by at least 90%. Although the effectiveness of dust suppression did not depend on blade type, a diamond blade was more effective than a resin-bonded blade with the pressurised water system; cutting a slab with this type of blade could be completed before the water tank required repressurization. In laboratory tests, the application of water reduced the dust concentration to < 4% of its value without control. The method for monitoring the dust concentration was sufficiently sensitive to measure a difference in concentration produced during cutting in different directions. It is important, however, that the pressure in supply reservoirs is properly maintained, that the water is correctly applied and that it is used at the correct rate. If this is done effective dust control can be achieved. (+info)
Measuring the noise attenuation of shotblasting helmets.
(48/1312)
Air-fed blasting helmets are used in abrasive blasting operations to provide essential face, eye and respiratory protection. BS EN 271: 1995 (equivalent to the European Standard EN 271: 1997), the standard that deals with the construction of blasting helmets, addresses the above matters and also the problem of noise generated by the breathing air supply. However it has no requirements for manufacturers to measure or report the helmet's ability to attenuate the very high levels of noise generated by the blasting process. The aim of the project was to develop a test method to measure the noise attenuation of shotblasting helmets. The method developed is an objective measurement, using a head and torso simulator (HATS), which provides a suitable means for helmet manufacturers to report their product's ability to attenuate blasting noise. The results from this project showed that the HATS currently prescribed by BS EN 271: 1995 can be used for measuring the noise attenuation of helmets against typical shotblasting noise. Using such a HATS in the proposed test method will give attenuation values that correlate well with those measured using human subjects. Therefore the HATS already used by manufacturers to show compliance of their product with BS EN 271: 1995 could also be used to provide information on the helmet's noise attenuation. Results from this project also showed that the same HATS can be used, in place of human subjects, to measure the air supply noise according to the method defined in BS EN 271: 1995. BS EN 271: 1995 is due for revision in 2000. The results from this work should be used to influence future revisions of the standard so that requirements to measure and report noise attenuation of shotblasting helmets are considered, a major omission in the present standard. (+info)