[Air pollution, asthma and allergy--the importance of different types of particles]. / Luftforurensning, astma og allergi--betydningen av ulike partikler.

BACKGROUND: Particulate air pollution has been much discussed in Norway during the last few years. Coarse particles from asphalt are likely to have quite different properties than the far smaller particles from diesel exhaust. MATERIALS AND METHODS: On the basis of data from the literature and our own research, we discuss the health problem of different types of particles with a focus on allergy and respiratory symptoms. RESULTS: Diesel exhaust particles have well-documented adverse effects in relation to allergic airway disease. They increase symptoms load in already allergic individuals and also seem to contribute to the increased prevalence of allergy. PM10 is today measured on the basis of weight, not on number. Diesel exhaust particles are much smaller than road surface particles; hence PM10 measurements reflect road surface dust pollution more than exhaust particles. INTERPRETATION: Focus should now be given to diesel exhaust particles in order to reduce the adverse health effects of particulate air pollution in Norwegian cities.

Effects in the eyes caused by exposure to office dust.

This Danish Office Dust Experiment compares the responses of 24 normal non-sensitive adult subjects to exposure to normal office dust in the air at 136 and 390 micrograms/m3 (median) and to their responses in clean air. The exposure duration was 5 1/4 h in a climate chamber under controlled conditions. The dust had no major identifiable specific reactive compounds. The overall conclusion is that healthy subjects without any hypersensitive reactions seem to respond to exposure to the house dust. The effects observed were all found in interaction with response modifying factors. The effects were a decrease in inflammatory cells in tear fluids, increased epithelium defects, and a decrease in break-up time. No effect was seen on eye reddening, or eye sensitivity to CO2. As no specific hypotheses could be specified before the study for the observed interactions, no definitive conclusions can be made. Furthermore, it seemed that there was no consistency in the interacting factors after the exposure and the next morning. A tentative analysis of the effects of the importance of personal characteristics showed that only a minority within the subject group may respond to the exposure. However, no common set of sensitivity measures could be defined for these responders.

Induction of ferritin and lipid peroxidation by coal samples with different prevalence of coal workers' pneumoconiosis: role of iron in the coals.

BACKGROUND: Differences in levels of bioavailable iron (BAI) in coal may be responsible for the observed regional differences in the prevalence and severity of coal workers' pneumoconiosis (CWP). METHODS: Twenty-nine coal samples from three coal mine regions were tested in human lung epithelial Type II A549 cells. They were from Utah (UT), West Virginia (WV), and Pennsylvania (PA) with a prevalence of CWP of 4, 10, and 26%, respectively. RESULTS: Low molecular weight (LMW) chelators bound iron, a fraction of BAI in the cells released from coals, ferritin, and lipid peroxidation were significantly higher in cells treated with various coals than in control cells, with an increasing order of UT < WV < PA, in parallel to the prevalence of CWP in these coal mine regions. Deferoxamine (DFO), a specific iron chelator, was used to distinguish effects of BAI from those of other transition metals. Our results indicate that BAI in the coals of WV and UT is the main metal species in inducing ferritin and lipid peroxidation. In contrast, biological effects of PA coals are not only from BAI, but from other transition metals as well. CONCLUSIONS: Based on a large number of coal samples from various seams, the findings of this study provide further evidence that metals, particularly iron, play important roles in coal dust-induced cellular damage, ultimately leading to the development of CWP and contributing to the regional differences in the prevalence of the disease.

Acute eosinophilic pneumonia in a New York City firefighter exposed to World Trade Center dust.

We report a sentinel case of acute eosinophilic pneumonia in a firefighter exposed to high concentrations of World Trade Center dust during the rescue effort from September 11 to 24. The firefighter presented with a Pa(O2) of 53 mm Hg and responded to oxygen and corticosteroids. Computed tomography scan showed patchy ground glass density, thickened bronchial walls, and bilateral pleural effusions. Bronchoalveolar lavage recovered 70% eosinophils, with only 1% eosinophils in peripheral blood. Eosinophils were not degranulated and increased levels of interleukin-5 were measured in bronchoalveolar lavage and serum. Mineralogic analysis counted 305 commercial asbestos fibers/10(6) macrophages including those with high aspect ratios, and significant quantities of fly ash and degraded fibrous glass. Acute eosinophilic pneumonia is a rare consequence of acute high dust exposure. World Trade Center dust consists of large particle-size silicates, but fly ash and asbestos fibers may be found in bronchoalveolar lavage cells.

Early sensitization to house dust mite is a major risk factor for subsequent development of bronchial asthma in Japanese infants with atopic dermatitis: results of a 4-year followup study.

BACKGROUND: Bronchial asthma (BA) often develops in children with atopic dermatitis (AD). Identification of factors that could predict the development of asthma in children with AD is useful for early intervention. OBJECTIVE: We undertook a 4-year followup study to clarify the factors involved in the development of BA in infants with AD. METHODS: We registered 169 infants with AD who were free of BA at registration and examined the prevalence and characteristics of the subsequent development of BA among these patients. RESULTS: Among the patients followed for 4 years, approximately 45% experienced asthma-like respiratory symptoms, and 35% were diagnosed as asthmatic patients by pediatric allergologists. Patients who developed BA showed early appearance of house dust mite (HDM)-specific immunoglobulin E (IgE) and persistently high levels of food-specific IgE. Male sex, a positive family history of BA, and the appearance of HDM-specific IgE were identified as significant risk factors for the early development of BA, but the significance of these parameters decreased thereafter. A positive family history of AD, the outcome of skin lesions, and keeping furred pets were also identified as risk factors in a part of the followup period. Among the parameters examined, the early appearance of HDM-specific IgE was the most significant risk factor. CONCLUSION: Appearance of HDM-specific IgE antibodies in early childhood, which seems to be mainly influenced by genetic factors, is a major risk factor for the subsequent development of BA in children with AD, but the influence decreases after longer followup.

Occupational dust exposure and the risk of laryngeal cancer in Turkey.

OBJECTIVES: A hospital-based case-referent study was conducted to identify occupational risk factors for laryngeal cancer. In a previous report an association was found between laryngeal cancer and occupations with potential dust exposure; a job-exposure matrix was developed to aid further evaluation of laryngeal cancer risks from five occupational dust exposures. METHODS: Among 7631 cancer cases from the Okmeydani Hospital, Istanbul, between 1979 and 1984, 958 larynx cancer cases were identified among men. After exclusions, 940 laryngeal cancer cases and 1519 referents were available. A standardized questionnaire was used to obtain basic information on the patients. Seven-digit standard occupational and industrial codes were created to classify the job and industrial titles. A job-exposure matrix was developed for occupational dusts, including silica, asbestos, wood, cotton, and grain, and age-, smoking-, and alcohol-adjusted odds ratios (OR) and 95% confidence intervals (95% CI) were calculated to evaluate risks of laryngeal cancer. RESULTS: An excess of laryngeal cancer occurred for workers potentially exposed to silica and cotton dust, particularly for supraglottic cancer (OR 1.8, 95% CI 1.3-2.3, for silica and OR 1.6, 95% CI 1.1-2.5, for cotton dust), and there was a significant dose-response relationship with silica exposure. No relationship was found between laryngeal cancer and asbestos, grain, or wood dust exposures. CONCLUSION: Laryngeal cancer, especially supraglottic tumors, is associated with silica and cotton dust exposures in Turkey.

Clinical evaluation of the effect of anti-allergic mattress covers in patients with moderate to severe asthma and house dust mite allergy: a randomised double blind placebo controlled study.

BACKGROUND: The use of anti-allergic mattress covers in patients with asthma can result in a large reduction in the level of house dust mite allergen in dust samples. Apart from a reduction in histamine induced bronchial hyperresponsiveness, there are few data on the effect of mattress covers on clinical efficacy and quality of life in patients with moderate to severe asthma. METHODS: Thirty patients with asthma and house dust mite allergy were studied in a randomised, double blind, placebo controlled study. Before and after using anti-allergic covers for 1 year, dust was collected from the mattresses to determine concentrations of Dermatophagoides pteronyssinus (Der p 1), and bronchial hyperresponsiveness and quality of life were measured. The patients scored their symptoms (lungs and nose), morning and evening peak flow values, and rescue medication for 14 days before and after the intervention period. RESULTS: There was a significant reduction in the concentration of Der p 1 in the dust collected from the mattresses in the actively treated group after 1 year compared with before treatment; no change was found in the placebo group. In both the actively treated and placebo groups there was no significant improvement in PC(20) histamine. Quality of life improved similarly in both groups. The symptom score of the lower airways did not significantly change in either group. A significant decrease in nasal symptom score was seen in the actively treated group compared with before treatment, but there was no significant difference between the groups. No changes in morning and evening peak flow values, peak flow variability, nor in the use of rescue medication were found in either group. CONCLUSION: The use of anti-allergic mattress covers results in significant reductions in Der p 1 concentrations in carpet-free bedrooms. However, in patients with moderate to severe asthma, airways hyperresponsiveness and clinical parameters are not affected by this effective allergen avoidance.

Effectiveness of a worksite intervention to reduce an occupational exposure: the Minnesota wood dust study.

OBJECTIVES: This study assessed the effectiveness of an intervention to reduce wood dust, a carcinogen, by approximately 26% in small woodworking businesses. METHODS: We randomized 48 businesses to an intervention (written recommendations, technical assistance, and worker training) or comparison (written recommendations alone) condition. Changes from baseline in dust concentration, dust control methods, and worker behavior were compared between the groups 1 year later. RESULTS: At follow-up, workers in intervention relative to comparison businesses reported greater awareness, increases in stage of readiness, and behavioral changes consistent with dust control. The median dust concentration change in the intervention group from baseline to follow-up was 10.4% (95% confidence interval = -28.8%, 12.7%) lower than the change in comparison businesses. CONCLUSIONS: We attribute the smaller-than-expected reduction in wood dust to the challenge of conducting rigorous intervention effectiveness research in occupational settings.

Dermatitis caused by physical irritants.

BACKGROUND: Although physical irritant contact dermatitis (PICD) is a common occupational dermatosis, it is one of the least well understood because of its multiple types, lack of diagnostic test, and the many mechanisms involved in its production. OBJECTIVES: To characterize the materials and mechanisms of physical irritation of the skin. METHODS: We did a retrospective analysis over the past 20 years of all patients with a diagnosis of PICD at St John's Institute of Dermatology Contact Dermatitis Clinic. RESULTS: Of the 29,000 patients who attended the clinic over the study period, 392 patients were diagnosed with PICD and of these, 335 files were analysed. CONCLUSIONS: Our findings show that PICD accounted for 1.15% of all patients attending the contact clinic over the study period. Diverse occupations and materials were implicated. The most common cause of PICD was low humidity due to air-conditioning, which caused dermatitis of the face and neck in office workers due to drying out of the skin.

Trimellitic anhydride (TMA) dust induces airway obstruction and eosinophilia in non-sensitized guinea pigs.

Trimellitic anhydride (TMA) causes asthma after a latency period of sensitization. In non-sensitized humans and animals, limited studies indicate that TMA exposure may also cause symptoms of asthma without a latency period. Our previous studies (J. Pharmacol. Exp. Ther. 296 (2001) 284) in a guinea pig model of TMA-induced asthma demonstrated that sensitization and the complement system were required for eosinophilia. TMA conjugated to guinea pig serum albumin (TMA-GPSA) was used to elicit the response. Since occupational exposure to TMA occurs by inhalation of dust, the present studies determined if exposure to TMA dust in a non-sensitized guinea pig elicited airway obstruction and inflammation, and whether a significantly greater response occurred after a latency period of sensitization. Guinea pigs were intradermally injected with either corn oil (non-sensitized animals) or 30% TMA (sensitized animals). Three weeks later they were challenged by intratracheal insufflation with 1 mg TMA dust or lactose dust (control) using a dry powder delivery device. Pulmonary resistance, dynamic lung compliance, mean arterial blood pressure and heart rate were monitored for 10 min. In non-sensitized guinea pigs, significant increases in pulmonary resistance and decreases in dynamic lung compliance and blood pressure occurred after TMA challenge. In sensitized animals, the same dose of TMA caused significantly greater effects compared to non-sensitized animals. In a separate experiment, cellular infiltration into the lung was determined 24 h after challenge with TMA dust or lactose dust. In both non-sensitized and sensitized animals, eosinophils in the lung tissue were increased after TMA dust challenge compared to controls. Thus, these studies suggest that the response in non-sensitized animals differs depending on whether TMA dust or TMA-GPSA is used to elicit the response. TMA dust elicits significant airway obstruction and eosinophilia in a non-sensitized animal, with even greater airway obstruction occurring in a sensitized animal.

Placebo-controlled trial of house dust mite-impermeable mattress covers: effect on symptoms in early childhood.

We investigated the effect of house dust mite (HDM)-allergen avoidance on the development of respiratory symptoms, atopic dermatitis, and atopic sensitization by performing a double blind, placebo-controlled trial. In total, 1,282 allergic pregnant women were selected (416 received HDM allergen-impermeable mattress covers for the parents' and child's mattress in the third trimester of pregnancy [active], 394 received placebo covers, 472 received no intervention). Data on allergen exposure, clinical symptoms, and immunoglobulin E were collected prospectively. The prevalence of night cough without a cold in the second year of life was lower in the group with active covers compared with the group with placebo covers (adjusted odds ratio 0.65; 95% confidence interval 0.4-1.0). No effect of the intervention was seen on other respiratory symptoms, atopic dermatitis, and total and specific immunoglobulin E. It can be concluded that application of HDM-impermeable mattress covers on the child's and parents' beds reduced night cough, but not other respiratory symptoms, atopic dermatitis, and atopic sensitization in the first 2 years of life. Follow-up will determine the long-term effect of the intervention on the development of atopic disease.

[Chronic obstructive pulmonary disease (COPD) and occupational exposure to mineral dust]. / Broncopneumopatia cronica ostruttiva (BPCO) ed esposizione professionale a polveri minerali.

The relationship between chronic obstructive pulmonary disease (COPD) and occupational exposure to mineral dust is still conflicting because COPD is multifactorial disease, relatively common in the general population. A number of studies have shown that in population exposed to mineral dust there is a greater prevalence of chronic bronchitis, even in the absence of radiographic evidence of pneumoconiosis. There is no agreement, however, that dust alone will induce significant chronic airflow limitation and increase in mortality. It is unlikely that medical evidence could ever provide conclusive "proof" of the work related less of COPD in the singular patient, but it is possible to provide evidence for reasonable statment of probability.

Differences in the effects of fibrous and particulate titanium dioxide on alveolar macrophages of Fischer 344 rats.

Alveolar macrophages are considered to play a major role in the pathophysiology of lung diseases caused by exposure to various kinds of pathogens and particles. In this study, the cytotoxic effect of different shapes of titanium dioxide (TiO(2)) was evaluated on macrophages using a unique magnetometry method and was compared with conventional methods of lactate dehydrogenase (LDH) release, apoptosis measurement, and morphological observations. Alveolar macrophages obtained from Fischer rats (F344) by bronchoalveolar lavage were incubated in vitro for 18 h with Fe(3)O(4) as a magnetometric indicator and fibrous and particulate forms of TiO(2) as test materials. In the control and particulate exposed group, rapid attenuation of the residual magnetic field, so-called "relaxation," was observed immediately after cessation of the external magnetic field. In comparison, a delay of relaxation was observed in alveolar macrophages exposed to fibrous TiO(2). LDH released into serum-free medium induced by exposure to TiO(2) increased significantly in a concentration-dependent manner in macrophages exposed to fibrous TiO(2), while negligible LDH release was observed in macrophages exposed to particulate TiO(2). The DNA ladder detection method and morphological examination detected no apoptosis in macrophages exposed to 60 micro g/ml of fibrous or particulate TiO(2). Electron microscopic examination revealed vacuolar changes and cell surface damage in macrophages exposed to fibrous TiO(2), but no significant changes in macrophages exposed to particulate TiO(2). The results of magnetometry, LDH release, and electron microscopy suggest that cytotoxicity of TiO(2) depends on the shape of the material.

[A case of occupational asthma caused by Ayous wood (Triplochiton scleroxylon)].

A 58-year-old man, a carpenter, had been suffering from cough, rhinorrhea, wheezing, dyspnea and ocular itching a few minutes after each exposure to the sawdust of "Ayous" wood (Obeche, Triplochiton scleroxylon) since starting to work on this imported wood in 1998. Although his symptoms improved soon after exposure, he had a secondary response several hours later. He had no symptoms when working with any other woods. In January, 2001, he came to our hospital, and occupational asthma was suspected. Peak flow monitoring revealed immediate- and late-type responses when he was exposed to Ayous wood dust. Non-specific bronchial hyperresponsiveness to acetylcholine was positive. An immediate skin test with Ayous wood extract was positive. In the RAST inhibition test, his serum revealed specific IgE antibody to Ayous extract. Bronchoprovocation with Ayous wood extract demonstrated immediate and later type responses (dual response). Occupational asthma caused by Ayous wood dust was confirmed. This is the first case report of occupational asthma caused by Ayous wood in Japan.

[Main difficulties and advances in State sanitary and epidemiological supervision of occupational health in Voronezh region]. / Osnovnye problemy i perspektivy razvitiia gosudarstvennogo sanitarno-épidemiologicheskogo nadzora po gigiene truda v Voronezhskoi oblasti.

Creation of favorable work conditions necessitates gradual change-over to their specification on major industrial workplaces with intensive occupational hazards.

[Complex hygienic evaluation of drivers' work conditions]. / Kompleksnaia gigienicheskaia otsenka uslovii truda voditelei.

Drivers' work is characterized by various occupational hazards--higher psychoemotional strain associated with risk of traffic accidents, unfavorable microclimate, dusty and polluted air, static physical load.

[Characteristics of work environment factors and health state of workers engaged in open mining of refractory clay and structural quartz sand]. / Kharakteristika faktorov proizvodstvennoi sredy i zdorov'ia rabochikh pri otkrytoi dobyche ogneupornoi gliny i stroitel'nykh kvartsevykh peskov.

This article covers evaluation of work conditions and health state in workers engaged into open-cast extraction of refractories and of building quartz sand in moderate climate of Voronezh region.

[Occupational medicine in present-day furniture production]. / Voprosy meditsiny truda v sovremennom mebel'nom proizvodstve.

Work conditions in furniture production are characterized by complex of occupational hazards: dusty and polluted air, local vibration, noise, static physical strain.