Indoor radon risk associated to post-tectonic biotite granites from Vila Pouca de Aguiar pluton, northern Portugal.

At Vila Pouca de Aguiar area, northern Portugal, crops out a post-tectonic Variscan granite pluton, related with the Régua-Vila Real-Verín fault zone, comprising three types of biotite granites. Among these granites, PSG granite yield the highest average contents of U, probably due to its enrichment in accessory U-bearing minerals such as zircon. In the proximity of faults and joints, these granites are often affected by different degrees of hydrothermal alteration, forming reddish altered rocks, commonly known as "episyenites". These altered rocks are probably associated to the occurrence of hydrothermal processes, which led to uranium enrichment in the most advanced stages of episyenitization. In these granites, both average gamma absorbed dose rates in outdoor and indoor air are higher than those of the world average. Furthermore, even in the worst usage scenario, all these granites can be used as a building material, since their annual effective doses are similar to the limit defined by the European Commission. The geometric mean of radon activity of 91 dwellings located at the Vila Pouca de Aguiar pluton is 568Bqm(-3), exceeding that of other northern Portuguese granites. Measurements carried out during a winter season, indicate that 62.6% of the analysed dwellings yield higher indoor radon average values than the Portuguese legislation limit (400Bqm(-3)), and annual effective doses due higher than the world's average value (1.2mSvy(-1)). The interaction of geogenic, architectural and anthropogenic features is crucial to explain the variance in the geometric mean of radon activity of dwellings from Vila Pouca de Aguiar pluton, but the role of geologic faults is probably the most important decisive factor to increase the indoor radon concentration in dwellings. Hence, the development of awareness campaigns in order to inform population about the incurred radiological risks to radon exposure are highly recommended for this specific area.

Assessment of indoor absorbed gamma dose rate from natural radionuclides in concrete by the method of build-up factors.

The specific absorbed gamma dose rates, originating from natural radionuclides in concrete, were calculated at different positions of a detection point inside the standard room, as well as inside an example room. The specific absorbed dose rates corresponding to a wall with arbitrary dimensions and thickness were also evaluated, and appropriate fitting functions were developed, enabling dose rate calculation for most realistic rooms. In order to make calculation simpler, the expressions fitting the exposure build-up factors for whole (238)U and (232)Th radionuclide series and (40)K were derived in this work, as well as the specific absorbed dose rates from a point source in concrete. Calculated values of the specific absorbed dose rates at the centre point of the standard room for (238)U, (232)Th and (40)K are in the ranges of previously obtained data.

Suicide-related perforating injury of globe with nail gun.

A case is reported of nail gun injury due to suicide attempt involving both orbits, frontal lobe and abdomen, which resulted in an unusual posterior perforation of the left globe. Injury was inflicted with a total of eight nails. Three nails entered the left orbit, one of which perforated the posterior aspect of the left globe. One nail entered the right orbit involving the optic nerve and crossed the midline to finish in the left sphenoid sinus. Three nails entered the frontal lobe near the midline and the final nail pierced the left lobe of the liver. The left eye underwent primary repair, lensectomy and vitrectomy with silicone oil and achieved a visual acuity of 6/60, 3 months post removal of oil with sutured posterior chamber intraocular lens. The right eye suffered traumatic optic neuropathy and currently has a visual acuity of 6/36 due to senile cataract formation. No other serious sequelae resulted from the other injuries and the patient has recovered from his episode of depression.

Emission patterns and emission rates of MVOC and the possibility for predicting hidden mold damage?

UNLABELLED: Laboratory trials were performed in order to search for the variety of the production of microbial volatile organic compounds (MVOC), which could be used as indicators for hidden mold damage. Concerning MVOC production the experiments showed a dependency on the mold genus/species, the different strains used and the building materials used as substrate. It could be proved that the production of certain MVOC is not consistent at all times. On the whole low emission rates in terms of microg/h/m2 of the MVOC were found. Extrapolating the emissions rates from the laboratory trails to an indoor air situation results in concentrations below the analytical detection limit in most cases. According to these results only heavy or very large fungal contaminations might be detected by this method in indoor air. The studies were performed at the Institute of Hygiene and Environmental Medicine, Charite, Germany. PRACTICAL IMPLICATIONS: Microorganisms like bacteria and molds produce a huge variety of substances, and a part of them are released into the environment. Some compounds like, e.g. alcohols or ketones are volatile, therefore found in the air and called MVOC. Those compounds were considered helpful to track especially hidden mold damage. The study presented here showed, that the emission pattern varies from genus to genus and sometimes even from fungal strain to fungal strain. The results concerning the emission rates from different infested building materials proved, that the concentrations produced are much too low to be detected in indoor air, especially considering the dilution because of ventilation. Therefore, we conclude that MVOC should not be used as predictors for mold damage in indoor environments.

Patch test results in 542 patients with suspected contact dermatitis in Turkey.

In this retrospective study, patch test results of 542 patients (303 female and 239 male), referred to our clinic between June 1996 and July 1999, were evaluated. All patients were patch tested with 32 allergens of an extended European standard series, 140 patients were tested with supplemental series, and 246 patients with their own substances. 280 (51.7%) patients had 1 or more positive results but allergic contact dermatitis, according to clinical relevance, was diagnosed in only 190 (67.9%) of these. Nickel sulfate was the most frequent sensitizer (19.1%), followed by potassium dichromate (11.8%), palladium chloride (9.4%), cobalt chloride (8.5%), and thiuram mix (7.7%). Frequencies of contact allergy to fragrance mix (5.5%), balsam of Peru (Myroxylon Pereirae resin) (2%), quaternium-15 (0.6%), and Kathon CG (methylchloroisothiazolinone+methylisothiazolinone) (0.2%) were relatively low, while no positive reactions were obtained to paraben mix in any case. Current clinical relevance to the present dermatitis was most frequently seen with carba mix (96.2%), thiuram mix (95.2%) and potassium dichromate (78.1%), whereas this rate was low for nickel (37.5%). In 85.8% of patients with allergic contact dermatitis, the responsible allergen was detected by testing with the extended standard series alone (18.4% identified by testing with the additional 10 allergens), in 11.6% by testing with the patients' own substances, and in 2.6% by testing with the supplemental series. Occupational contact dermatitis was diagnosed in 77 of the patients with positive reactions (27.5%), most of these being construction workers and house painters who showed relevant sensitizations to potassium dichromate, cobalt chloride, thiuram mix and carba mix. There was no statistically significant difference in the total contact sensitization rate between atopics and non-atopics, but contact sensitivity to nickel sulfate and palladium chloride was significantly higher among atopics. MOAHL index in % was: 44.1/14.2/24.9/ 54.4/2.4. In conclusion, we believe that similar large series of patients would be helpful to delineate the exact profile of contact dermatitis in Turkey.

Hypersensitivity pneumonitis in workers exposed to esparto grass (Stipa tenacissima) fibers.

Esparto grass (Stipa tenacissima), which is commonly found in the Mediterranean countries, has a wide variety of uses. Five stucco makers who had cough, dyspnea, malaise, and fever after exposure to esparto fiber used in their jobs showed a significant decrease in symptoms when they were away from work. Precipitating antibodies against an esparto extract were found in the sera of all patients. Specific IgG antibodies against the esparto extract were also demonstrated in all patient sera, as were IgG antibodies to Aspergillus fumigatus and thermophilic microorganisms (Micropolyspora faeni and Thermoactinomyces vulgaris) by means of an ELISA method. Esparto activity was inhibited in different ranges by the above antigens by inhibition ELISA. Only A. fumigatus could be identified after microbiologic evaluation of the esparto fiber samples. After inhalation challenge tests were performed with esparto extracts, all patients showed significant decreases in forced vital capacity, transfer lung CO, and PaO2 blood gas from baseline values. Fever, chills, malaise, dry cough, tachycardia, tachypnea, and rales on chest auscultation were also observed in all patients. Findings from bronchoalveolar lavage were suggestive of allergic alveolitis. Transbronchial biopsy specimens showed interstitial alveolitis with lymphocyte-macrophage infiltrate and granuloma. Unexposed control subjects did not exhibit reactivity to any of the tests listed above. The dust derived from esparto fibers can cause hypersensitivity pneumonitis in exposed subjects. Organisms such as A. fumigatus and thermophilic actinomyces could be the causative antigens. "Stipatosis" might be an appropriate name for this disorder.

Carbon monoxide poisoning from use of gasoline-fueled power washers in an underground parking garage--District of Columbia, 1994.

On June 17, 1994, five workers in the District of Columbia were treated in an emergency department for carbon monoxide (CO) poisoning following exposure to the exhaust from two gasoline-fueled power washers (i.e., pressure washers), which they had used in an empty underground parking garage. These cases were identified by The George Washington University (GWU) Division of Occupational and Environmental Medicine (DOEM) through ongoing surveillance for work-related injuries among construction workers treated in the GWU emergency department (1). This report summarizes the results of an investigation by DOEM of this incident.

Elemental mercury vapour toxicity, treatment, and prognosis after acute, intensive exposure in chloralkali plant workers. Part II: Hyperchloraemia and genitourinary symptoms.

Exposure to elemental mercury vapour is known to influence renal function; however, severe renal disease has not been consistently identified. Eleven men were evaluated for renal disease after acute, massive mercury poisoning. Significant hyperchloraemia was identified in this group of patient and a reversible renal tubular defect was suggested by low normal serum bicarbonate, a normal serum anion gap and a positive urinary anion gap. The only other evidence of renal dysfunction was transient, mild proteinuria in one of the 11 patients. During this same time period, neuropsychological impairment was identified on a test of cognitive and visual-motor function, 'Trailmaking B', in seven of the 11 patients. Additionally, dysuria and ejaculatory pain occurred without evidence of urological disease. These complaints were more frequent in those patients with impairment on 'Trailmaking B' suggesting a neurological basis for these symptoms. The findings of this study support earlier observations that the brain rather than the kidney is the critical target organ after elemental mercury vapour exposure.

Elemental mercury vapour toxicity, treatment, and prognosis after acute, intensive exposure in chloralkali plant workers. Part I: History, neuropsychological findings and chelator effects.

Mercury poisoning occurred after the acute, prolonged exposure of 53 construction workers to elemental mercury. Of those exposed, 26 were evaluated by clinical examination and tests of neuropsychological function. Patients received treatment with chelation therapy in the first weeks after exposure. Eleven of the patients with the highest mercury levels were followed in detail over an extended period. Observations included the evaluation of subjective symptoms of distress, using the 'Symptom Check List 90-Revised' (SCL-90R) and tests of visual-motor function such as 'Trailmaking Parts A and B', 'Finger Tapping', 'Stroop Colour Word Test' and 'Grooved Pegboard.' On day 85 +/- 11 (mean +/- s.d.) after exposure, these 11 men again received either 2,3-dimercaptosuccinic acid (DMSA) or N-acetyl-D, L-penicillamine (NAP) in a short-term study designed to compare the potential to mobilize mercury and the incidence of drug-induced toxicity of these two chelating agents. Rapidly resolving metal fume fever was the earliest manifestation of symptoms. CNS symptoms and abnormal performance on neuropsychological tests persisted over the prolonged period of follow-up. There were significant correlations between neuropsychological tests and indices of mercury exposure. Serial mercury in the blood and urine verified the long half-life and large volume of distribution of mercury. Chelation therapy with both drugs resulted in the mobilization of a small fraction of the total estimated body mercury. However, DMSA was able to increase the excretion of mercury to a greater extent than NAP. These observations demonstrate that acute exposure to elemental mercury and its vapour induces acute, inorganic mercury toxicity and causes long-term, probably irreversible, neurological sequelae.

Tooth surface loss among people exposed to cement and stone dust in the work environment in Tanzania.

The effect of cement and stone dust on teeth was explored in a cross-sectional study, using blind dental examinations. The sample consisted of 36 workers who had been exposed to to the dust and 62 control workers. Tooth surface loss was observed in 72.2 per cent of the exposed workers and in 48.4 per cent of the controls (P less than 0.03). In both the maxillae (P less than 0.001) and the mandible (P less than 0.02) the amount of tooth surface loss was greater in the exposed workers than in the controls. Both anterior and posterior teeth were affected. These findings indicate that tooth surface loss caused by work-related dust should be considered an occupational hazard.

Pulmonary alveolar proteinosis and cement dust: a case report.

Pulmonary alveolar proteinosis developed in a 29-year-old white man within 2 years of working as a cement truck driver. Pulmonary alveolar proteinosis (PAP), an uncommon respiratory disorder characterized by the accumulation of phospholipid material within the alveoli, has been described in association with exposure to silica, aluminum oxide, and a variety of dusts and fumes. Although a link between exposure to Portland cement and PAP has not been previously noted, this type of cement contains nearly 20% silica. Lung biopsy material, originally used to diagnose PAP, was reviewed under electron dispersive spectroscopy. Analysis indicated the presence of silica particles within the alveolar fluid and macrophages. A number of items support a causal relationship between exposure to cement dust and PAP: (1) the temporal sequence between assuming job duties and the development of the illness, (2) improvement following removal from further exposure, (3) dusty, unprotected working conditions, (4) the presence of silica within the cement, and (5) the alveolar fluid from periodic acid-Schiff-positive lung tissue.

[Corneal sensitivity in workers in contact with petroleum products]. / Czucie rogówki u pracowników majacych kontakt z pochodnymi ropy naftowej.

Evaluation of the corneal sensitivity was carried out in 251 workers who have had a direct contact with petrol and its derivates and in 45 persons of a control group. It was established that the corneal sensitivity--especially in its central region--was distinctly lowered in persons employed in the department of asphalt oxidation and cleaning of sewages. This concerned particularly the workers with a long-lasting, many years service.

Ten years of epidemiologic investigations on man-made mineral fibers and health.

This paper introduces the reports that follow it in a supplement dealing with the extended follow-up of mortality and cancer incidence among workers in the man-made mineral fiber (MMMF) production industry in Europe, the largest international study of its kind thus far initiated. In addition it reviews the prior epidemiologic evidence on this subject, both in terms of the earlier results of the same study and the results of other studies on the long-term effects of occupational exposure to MMMF. The conclusion drawn from this prior evidence was that the possibility that some excess of lung cancer may be causally related to exposure to MMMF could not be ruled out of the range of reasonable interpretations. When the findings of the extended follow-up, which this paper introduces, are added to the existing evidence, the overall results were considered to endorse the indication that no adverse long-term health effects have been detectable in terms of mortality throughout almost all segments of the MMMF production industry and to support the inference that MMMF--as present in the environmental conditions of early slag-wool/rock-wool production--may have played a role in the causation of lung cancer.