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PubMedDate not supplied

Photodecomposition of 1-nitropyrene and other direct-acting mutagens extracted from diesel-exhaust particulates.

The effect of irradiation with wavelengths of 320-418 nm on direct-acting mutagenicity of 1-nitropyrene (1-NP) and particulate-matter extracts of a direct-injecting diesel engine was examined. The activity of samples in the Ames test with and without addition of S9 mix in Salmonella typhimurium strain TA98, TA100 and TA1538 decreased with increasing irradiation energy. Visible light was sufficient to destroy the mutagenicity of a 0.1-mM 1-NP solution. The same was true for particulate matter crude extracts as well as the transitional and oxygenate subfractions isolated by column chromatography. UV spectroscopy, thin-layer chromatography and GC-MS analysis were performed to characterize the irradiation products of 1-NP. The mechanism of photodecomposition of 1-NP at different wavelengths and the significance of this finding for the evaluation of health risks from diesel vehicles are discussed.

Air Pollutants↗
PubMed2000

Building sickness syndrome in healthy and unhealthy buildings: an epidemiological and environmental assessment with cluster analysis.

OBJECTIVES: Building sickness syndrome remains poorly understood. Aetiological factors range from temperature, humidity, and air movement to internal pollutants, dust, lighting, and noise factors. The reported study was designed to investigate whether relations between symptoms of sick building syndrome and measured environmental factors existed within state of the art air conditioned buildings with satisfactory maintenance programmes expected to provide a healthy indoor environment. METHODS: Five buildings were studied, three of which were state of the art air conditioned buildings. One was a naturally ventilated control building and one a previously studied and known sick building. A questionnaire was administered to the study population to measure the presence of building related symptoms. This was followed by a detailed environmental survey in identified high and low symptom areas within each building. These areas were compared for their environmental performance. RESULTS: Two of the air conditioned buildings performed well with a low prevalence of building related symptoms. Both of these buildings out performed the naturally ventilated building for the low number of symptoms and in many of the environmental measures. One building (C), expected to perform well from a design viewpoint had a high prevalence of symptoms and behaved in a similar manner to the known sick building. Environmental indices associated with symptoms varied from building to building. Consistent associations between environmental variables were found for particulates (itchy eyes, dry throat, headache, and lethargy) across all buildings. There were persisting relations between particulates and symptoms (headache, lethargy, and dry skin) even in the building with the lowest level of symptoms and of measured airborne particulates (building B). There were also consistent findings for noise variables with low frequency noise being directly associated with symptoms (stuffy nose, itchy eyes, and dry skin) and higher frequency noise being relatively protective across all buildings. CONCLUSIONS: This is the first epidemiological study of expected state of the art, air conditioned buildings. These buildings can produce an internal environment better than that of naturally ventilated buildings for both reported symptoms and environmental variables. The factors associated with symptoms varied widely across the different buildings studied although consistent associations for symptoms were found with increased exposure to particulates and low frequency noise.

Adult↗
PubMedDate not supplied

Effect of domestic concentrations of nitrogen dioxide on airway responses to inhaled allergen in asthmatic patients.

Nitrogen dioxide is a common indoor pollutant. In the light of suggestions that outdoor air pollution can harm people with asthma, we investigated the effect of 1 h exposures to domestic concentrations of nitrogen dioxide on the airway response to house-dust mite (HDM) allergen in ten patients with mild asthma. Each subject breathed air, 100 ppb nitrogen dioxide, or 400 ppb nitrogen dioxide for 1 h, in double-blind, random order, then immediately underwent a fixed-dose HDM challenge. Baseline forced expiratory volume in 1 s (FEV1) was not affected by any of the gas mixtures. The mean early asthmatic response (maximum percentage change in FEV1 during first 2 h after challenge) was -14.62% (SD 8.03) after air, -14.41% (7.86) after 100 ppb nitrogen dioxide, and -18.64% (7.28) after 400 ppb nitrogen dioxide. The difference between air and 400 ppb (-4.01%) was significant (95% CI -1.34 to -6.69%, p < 0.009), but those between air and 100 ppb and between 100 and 400 ppb were not (0.21 [-3.10 to 3.53]% and -4.23 [-8.75 to 0.29]%). The mean late asthmatic response (maximum percentage change in FEV1) to challenge after air was -2.85% (3.95), after 100 ppb nitrogen dioxide -7.76% (6.92), and after 400 ppb -8.13% (6.64). The difference in means between the air and 400 ppb exposures was significant (-5.28 [-0.73 to -9.83]%, p < 0.02) but those between air and 100 ppb (-4.90 [-10.60 to 0.78]%) and 100 and 400 ppb (0.37 [3.06 to 3.80]%) were not. These findings suggest that nitrogen dioxide, at concentrations encountered in the home environment, can potentiate the specific airway response of patients with mild asthma to inhaled HDM allergen, although the effect is small.

Adolescent↗
PubMed1999

Major avoidable risk factors of cancer.

With an aim of promoting primary prevention of cancer, major avoidable risk factors as well as protective factors of cancer are reviewed based on previous epidemiological studies. Among various risk factors of cancer, tobacco is the most important avoidable risk factor for cancers of the oral cavity, larynx, lung, pharynx, esophagus, stomach, liver, pancreas, kidney (pelvis), ureter, bladder, and cervix. Tobacco accounts for some 20-30% of all sites of cancer. Betel quid and tobacco chewing is an important risk factor for cancer of the oro-pharynx in some parts of South-East Asia. Diet also plays an important role in the etiology of cancer, but its relation to cancer is complicated. An excess or insufficient intake of some food components elevates risk of cancer of several sites. Eating habits, available foods, methods of food processing may vary from country to country. Infection of oncogenic viruses (especially, HBV, HVC, HPVs) is an important avoidable risk factor of cancer where liver cancer and cervical cancer are common. Infection of Helicobacter pylori could also be an important risk factor of stomach cancer. Attributable risks of other avoidable risk factors, such as occupation, environmental pollution, sun light, radiation, food additives, pesticides, drugs, etc. are relatively small compared to those of tobacco, diet and infection. Exercise and stress are also manageable risk factor of cancer.

Alcohol Drinking↗
PubMed2003

Miasmatic calories and saturating fats: fear of contamination in anorexia.

This paper draws on ethnographic material to challenge the taken-for-granted relationship between anorexia and fear of fat. While popular understandings assume anorexia to be an extension of everyday dietary guidelines and a fear of weight gain from foods high in fats and calories, I argue that it is fear of contamination rather than fear of fat per se that is at issue. Through a critique and extension of Mary Douglas' structuralist typology and Julia Kristeva's embodied theory of abjection, I demonstrate that it is the qualities of certain foods, and in particular their amorphous natures, that render them contaminating. Saturating fats and invisible calories are considered dangerous by people with anorexia because they have the ability to move, seep, and infiltrate the body through the interplay of senses. Foods that transgress conceptual and bodily boundaries are thus to be avoided at all costs, for they have the potential to defile and pollute. In light of the low recovery rates for those with anorexia within Australia (and internationally), the findings of this paper have significant implications for the understanding and treatment of this disorder.

Anorexia↗
PubMed2004

Review of ozone and temperature lidar validations performed within the framework of the Network for the Detection of Stratospheric Change.

The use of assimilation tools for satellite validation requires true estimates of the accuracy of the reference data. Since its inception, the Network for Detection of Stratospheric Change (NDSC) has provided systematic lidar measurements of ozone and temperature at several places around the world that are well adapted for satellite validations. Regular exercises have been organised to ensure the data quality at each individual site. These exercises can be separated into three categories: large scale intercomparisons using multiple instruments, including a mobile lidar; using satellite observations as a geographic transfer standards to compare measurements at different sites; and comparative investigations of the analysis software. NDSC is a research network, so each system has its own history, design, and analysis, and has participated differently in validation campaigns. There are still some technological differences that may explain different accuracies. However, the comparison campaigns performed over the last decade have always proved to be very helpful in improving the measurements. To date, more efforts have been devoted to characterising ozone measurements than to temperature observations. The synthesis of the published works shows that the network can potentially be considered as homogeneous within +/-2% between 20-35 km for ozone and +/-1 K between 35-60 km for temperature. Outside this altitude range, larger biases are reported and more efforts are required. In the lower stratosphere, Raman channels seem to improve comparisons but such capabilities were not systematically compared. At the top of the profiles, more investigations on analysis methodologies are still probably needed. SAGE II and GOMOS appear to be excellent tools for future ozone lidar validations but need to be better coordinated and take more advantage of assimilation tools. Also, temperature validations face major difficulties caused by atmospheric tides and therefore require intercomparisons with the mobile systems, at all sites.

Air Pollutants↗
PubMed2002

A novel approach for the oxidative degradation of organic pollutants in aqueous solutions mediated by iron tetrasulfophthalocyanine under visible light radiation.

An efficient approach has been developed to decompose toxic organic pollutants. The photodegradation of Rhodamine B (RhB), salicylic acid, and Orange II was examined in the presence of iron tetrasulfophthalocyanine ([Fe(PcS)]) and H(2)O(2) under visible irradiation. It was found that under visible light irradiation, organic pollutants in the [Fe(PcS)]/H(2)O(2) system can be rapidly degraded, but the concentration of [Fe(PcS)] remains nearly unchanged, and this indicates that [Fe(PcS)] has a good catalytic character. EPR results and other experimental results suggest that the light-activated reaction process involves the formation and reaction of HO(.) radicals. On the basis of the experimental results, a possible reaction mechanism for the degradation of organic pollutants under visible light illumination in the aqueous [Fe(PcS)]/H(2)O(2) solutions is proposed.

Azo Compounds↗
PubMedDate not supplied

An assessment of the effects of crude oil pollution on soil properties, germination and growth of maize (Zea mays) using two crude types--Forcados light and Escravos light.

The effect of crude oil pollution on soil properties, germination and height of maize (Zea mays) was investigated under natural environment in three separate pot experiments. Two crude oil types--Forcados light and Escravos light were used. In Experiment 1, the effect of crude oil application on germination using high pollution levels of 5, 15, 25 and 40 mL kg(-1) of soil was assessed. In Experiment 2, the effect of crude oil application on maize plant height using the same pollution levels was assessed. The last experiment (Experiment 3) was used to test for the effects of crude oil application on maize plant height using lower levels of pollution (1.0, 1.5, 2.0 and 2.5 mL kg(-1) of soil). Soil samples were collected before, during and after the experiment and analyzed for some physical and chemical properties. Results obtained showed variation in chemical properties of soil. % organic matter increased from 1.34 to 2.62% in polluted soils. Available P decreased from 15.00 ppm in control to between 7.34 and 5.42 in soils polluted with 'high' levels of crude oil. Statistical analysis of height data showed that crude oil inhibited the growth of maize at high pollution levels. High levels of pollution also inhibited germination and for Escravos light there was no germination at 40 mL kg(-1) soil level of crude oil pollution.

Dose-Response Relationship, Drug↗