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Free radicals, atherosclerosis, ageing, and related dysmetabolic pathologies: pathological and clinical aspects.

An excess of free-radical production has been linked to many diseases and to the ageing process. Oxidant by-products of normal metabolism can cause extensive damage to DNA, protein and lipid. Exposure to ultraviolet light, cigarette smoke and other environmental pollutants may also increase the free radical burden. The accumulation of unrepaired oxidative damage products is likely to be a major factor in cellular ageing. Many repair processes are available to the cell, including enzyme and structural defences. The large group of natural antioxidants is also part of a protective mechanism. High consumption of fruit and vegetables in the diet is associated with a lowered risk of degenerative diseases. At present, however, there are few data to support the routine use of exogenous antioxidants to prevent and treat these diseases.

Aged↗

The Stockholm Indoor Environment Questionnaire: a sociologically based tool for the assessment of indoor environment and health in dwellings.

The aim was to develop and validate a standardized questionnaire - the Stockholm Indoor Environment Questionnaire (SIEQ). The validation procedure was based on sociological principles and test procedures for validation. The indicators of indoor environment are air quality, thermal climate, noise, and illumination. The indicators of health are symptoms comprised in the sick building syndrome (SBS). The questionnaire also contains questions about the apartment, individual behavior, and personal factors. The everyday language describing the building and its function was first obtained by qualitative personal interviews, then by standardized questions. The interview questionnaire was transformed into a postal self-administered questionnaire. The reduction of the questionnaire was based on correlation analysis. It was found that to obtain a good validity, general questions are not sufficient, but specific question on perceptions and observations are needed. Good test-retest agreement was found both on an area level, building level, and individually. For each indicator, a set of questions are constructed and validated. SIEQ has been used in several studies, and the results are presented in graphic problem profiles. Reference data has been calculated for the Stockholm area.

Air Pollutants↗

Urban haze: the extent of automotive contribution.

Observation of the correlation between nitrogen oxides and the extinction coefficient of atmospheric air suggests that the automobile exhaust aerosol (nonphotochemical) may be important to visibility in cities.

Aerosols↗

Toxic metal fumes from mantle-type camp lanterns.

The mantle of a gas lantern contains about 600 micrograms of toxic beryllium metal. Most of the beryllium is volatilized and becomes airborne during the first 15 minutes of use of a new mantle. The inhalation of this quantity of beryllium can be hazardous.

Air Pollution↗

Assessment of contaminated sediments with an indoor freshwater/sediment microcosm assay.

This study was conducted to assess the feasibility of using a 2-L, indoor microcosm assay to evaluate five contaminated sediments (A, B, C, D, and E). Toxic potential was deduced in the light of general contamination of sediments, pollutant partitioning in microcosms, and biological responses of species (Pseudokirchneriella subcapitata, Lemna minor, Daphnia magna, Hyalella azteca, Chironomus riparius): E > A > B > C > D. Sediments mainly were contaminated by metals (lead and zinc). Organic pollutant contents varied among the sediments. The major polycyclic aromatic hydrocarbon (PAH) compounds were pyrene, fluoranthene, and phenanthrene. Sediments A, B, and C highly stimulated duckweed growth (> 700%) and impaired daphnid (< 20%) and amphipod survival (< 30%). Sediment D had no significant effect on pelagic and benthic organisms. Finally, sediment E, the most toxic, limited duckweed growth (inhibition of 82%) and impaired daphnid survival (0% of survival). Amphipods were impaired dramatically by this sediment (0% of survival), in contrast with chironomids, for which no toxic effect was measured. The 2-L, indoor microcosm assay successfully was applied to the assessment of those five contaminated sediments. Sediments A, B, C, and E should not be deposited in gravel quarries, and new, more sensitive endpoint measurements should be developed.

Animals↗

Membrane perturbations and mediation of gap junction formation in response to taurine treatment in normal and injured alveolar epithelia.

Nitrogen dioxide is an air pollutant that causes pulmonary alterations. Employing light and transmission electron microscopy, we examined plastic sections and freeze-fracture replicas of alveolar epithelium of groups of hamsters exposed to nitrogen for 24 h to determine taurine-induced changes in intercellular junctions. Prior to exposure, one group of hamsters was given 0.5% taurine in their drinking water for 2 weeks. A second group of hamsters was given taurine-free water. The taurine-treated group was divided into three subgroups. The first subgroup was exposed to nitrogen dioxide at a concentration of 7 ppm for 24 h, the second subgroup was exposed to nitrogen dioxide at a concentration of 30 ppm for 24 h, and the third subgroup was exposed to normal room air for 24 h. The nontaurine-treated animals were similarly divided into three subgroups and treated as described above. The lungs of the hamsters exposed to nitrogen dioxide without the taurine pretreatment exhibited extensive inflammatory cell infiltration in the walls of the terminal bronchioles, alveolar ducts, and peribronchiolar alveoli. The degree of infiltration was proportional to the degree of nitrogen dioxide concentration. The taurine-treated animals exposed to nitrogen dioxide and the nontaurine-treated animals exposed to room aid did not show any inflammatory infiltrate. Freeze-fracture replicas of the tight junctional regions of the type I and type II pneumocytes revealed significant fragmentation in the nitrogen dioxide-exposed lungs. It was also observed that the tight junctions between the type I pneumocytes of the taurine-treated groups, whether exposed or not, revealed gap junction-like aggregates among the tight junction fibrils. The 30-ppm nitrogen dioxide exposed group exhibited larger and more frequent gap junctions between the pneumocytes than those observed in the 7-ppm nitrogen dioxide exposed group. The evidence suggests that taurine may have an effect on plasma membranes and intercellular communications. Changes in intercellular communication may contribute to decreased susceptibility to injury and increased pneumocyte survival.

Animals↗

Physiological role of antioxidants in the immune system.

Diets contain naturally occurring antioxidant compounds that can stabilize highly reactive, potentially harmful molecules called free radicals. Free radicals are generated during normal cellular metabolism and result from the metabolism of certain drugs or xenobiotics. Exposure to UV light, cigarette smoke, and other environmental pollutants also increases the body's free radical burden. The harmful activities of free radicals are associated with damage to membranes, enzymes, and DNA. The ability of antioxidants to destroy free radicals protects the structural integrity of cells and tissues. This review focuses on data indicating that the functions of the human immune system depend on the intake of micronutrients, which can act as antioxidants. Recent clinical trials have found that antioxidant supplementation can significantly improve certain immune responses. Specifically, supplementation with vitamins C, E, and A or beta-carotene increased the activation of cells involved in tumor immunity in the elderly. Supplementation with the antioxidant vitamins also protected immune responses in individuals exposed to certain environmental sources of free radicals. Supplementation with vitamin A, a relatively weak antioxidant, decreases morbidity and mortality associated with measles infections in children.

Aging↗

[The relationship between work and vision in a preventive medicine context: the initial guidelines for a correct ergonomic ophthalmological approach proposed by the Italian Group for the Study of the Relationships between Work and Vision (G.I.L.V.). I. The presentation].

Modern technology poses numerous and complex problems concerning the implications for health in the work/vision relationship. While many of the hypotheses made in the past about the possibility of serious eye alterations in non-industrial workers have not been confirmed by recent investigations, considerable attention is at present being addressed to the short- and long-term effects of office work, especially in the case of tasks requiring prolonged visual effort "at near point". The prevalence of asthenopia in such workers is rather high, between 40 and 80%. The considerable specificity of the symptoms and the shortcomings in assessment of exposure in most of the research done so far has meant that no clear and unequivocal causal relationship between work involving intense visual effort and onset of asthenopia has been established. Nevertheless, from an analysis of the literature three main guidelines for a correct ergophthalmologic assessment can be identified: a) ophthalmologic assessments that will detect any transitory inefficiencies of the accommodation and convergence system; b) specific analysis of the technical and illumination conditions with special attention to the distribution of the natural and artificial light sources; c) quantification of airborne pollutants that have a potential irritative effect on the "ocular surface". Other environmental parameters that could be considered are electric and magnetic fields in the vicinity of VDTs and PCs and the microclimate of the workplace.

Ergonomics↗

[Polluted characteristics of Zn, Pb, Cd, Cu and As in soil of different mining activity zones].

Depending upon the polluted features of various mining activities in a typical nonferrous metal mine, the contaminated soil area was divided into four zones which were polluted by tailings, mine drainage, dust deposition in wind and spreading minerals during vehicle transportation respectively. In each zone, soil samples were collected. Total 28 soil samples were dug and be analyzed by ICP-AES and other relevant methods. The results indicated that the average contents of Zn, Pb, Cd, Cu and As in soils were 508.6 mg x kg(-1), 384.8 mg x kg(-1), 7.53 mg x kg(-1), 356 mg x kg(-1) and 44.6 mg x kg(-1) respectively. But the contents of heavy metals in different zone have distinct differences. The pollution intension of tailing was the heaviest which Nemero index was 17.3. Ranking of pollution intension of different zones from heavy to light is in the sequence of tailing zone, mineral transportation zone, mine drainage zone, and dust deposition zone. The original phase of heavy metals and minerals is the main pollution ingredient of each zone. The proportion of oxidizing association with organic substance is small. Difference of the association of heavy metals is small in different polluted zones.

Arsenic↗