Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Light Pollution”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39Linked to original sources
PubMed1995

[Nasal patency patterns observed during working hours in a group of technicians habitually exposed to formaldehyde].

Formaldehyde is a substance which is widely used in several work fields, including many medical and biological sectors. It appears that formaldehyde exposure may cause bronchial asthma. Little information is available, however, with regard to upper aereal tracts. The nose is a target organ of major importance for a large range of professional and extra-professional environmental pollutants. In particular, cases of professional rhinitis brought about by exposure to disinfectants have been reported in Literature. In the light of general knowledge related to the close correlation between upper and lower airways, and to the lack of information concerning the effects of short-term formaldehyde exposure on the upper aereal tract, the Authors decided that investigation of such exposure might prove interesting as well as worthwhile. A group of fifteen technicians who work in three different pathology departments and who had been exposed to formaldehyde for at least one year were studied. The purpose of the study was to assess possible alteration in nasal resistances at the end of a normal work shift. The subjects under study were observed according to a procedure which included several clinical, allergological, serological and functional evaluations carried out on specific days of the week. A control group, consisting of eight asymptomatic, non-atopic subjects who had never been exposed to inhalation of irritants was also monitored in the same way. Conclusions were drawn after considering some important variables such as exposure time, possible anatomical alterations of the nose, the presence of respiratory allergies and smoking habits. It was apparent that professional formaldehyde exposure typical of that experienced by technicians working in pathology departments induced a short-term irritant effect on the upper aereal tract, which, even though subclinical, is revealed by a statistically significant increase in nasal resistance. This effect seems to be favoured (at statistically not significant levels) by atopy, cigarette smoking and anatomical alterations of the nose. Our data seem to exclude a chronic cumulative effect of formaldehyde exposure.

Adult↗
PubMed1991

[Artemisia monosperma of the coastal plain as an allergen source in Jerusalem].

The possibility that pollen grains of Artemisia monosperma (AM) are transported to Jerusalem from their native habitat along the coastal plain was investigated. Air-borne pollen grains were sampled in the early autumn of 1989 with a Rotorod pollen sampler. During that period only 1 of the 4 species of AM in Israel, A. monosperma, was flowering. The sampling day was typical for the late summer, with a light NW breeze. Sampling was done simultaneously in 3 sites: Tel Aviv, Carmei Yosef and Jerusalem. The greatest concentration of pollen in Tel Aviv was found during the morning hours and decreased during the course of the day. Pollen counts in Carmei Yosef reached a maximum at 11:00 a.m. A substantial number of air-borne AM pollen was recorded in Jerusalem, with a daily peak at 1:00 p.m. Such results fit well the distribution pattern of the pollen as expected from the recorded wind velocity and direction. They also agree well with the data for transportation of other air pollutants from the coastal plain to Jerusalem. Apparently AM pollen is transported to Jerusalem over distances of many tens of kilometers, even on days with light winds. Therefore, such pollen may constitute an allergenic factor in Jerusalem in the autumn. It is reasonable to assume that transportation of pollens of other coastal plants follows a similar pattern.

Allergens↗
PubMed1981

Assessing consequences of marine pollution by hydrocarbons using sponges as model organisms.

Pollution has been assessed as a mutagenic activity determined by the Ames test, using radiolabelled benzo[a]pyrene (BaP) as a model pollutant. Experimental animals were sponges, mainly Tethya lyncurium from the Northern Adriatic and from the Pacific near Catalina Island, California, U.S.A. Changes in ornithine decarboxylase (ODC) activity (ODC; EC 4.1.1.17) and polyamine concentrations with and without pollution were observed. There is a slow rise in ODC activity during the course of three-weeks exposure and a fast increase of polyamine levels during the course of one day. Mixed function oxygenase (MFO; EC 1.14) activity could not be detected in sponges. There was a significant concentration dependent coupling of radioactive BaP derivatives (BaPD) to the macromolecular fractions; the highest in protein, X 1000 greater than DNA and X 500 greater than RNA. Coupling is light-mediated and drops to zero in the dark. However when activated microsomal fractions from fish, that had been exposed to high level polycyclic aromatic hydrocarbon (PAH) pollution are added, dark incorporation rises to significant levels which can be decreased by the MFO inhibitor 7,8-benzoflavone (BP). The question of possible absence of DNA repair in the sponges and some implications are discussed.

Animals↗
PubMed2003

Morphological effects in rat lungs exposed to urban roadside air.

We examined the effect of polluted roadside air on the pathogenesis of chronic respiratory diseases, by exposing rats directly to roadside air in Kawasaki City. Five-week-old Wistar rats were assigned to be exposed to either roadside air (containing 55.7 ppb NO2 and 62.7 microg/m(3) suspended particulate matter [SPM]; roadside-air group) or filtered air (containing 5.1 ppb NO2 and 14.3 microg/m(3) SPM; filtered-air group), prepared by eliminating dust and emission gas from the polluted roadside air, for a period of 60 consecutive wk. The morphological changes over time in the respiratory tissue of these animals were observed by light microscopy and electron microscopy at 24, 48, and 60 wk of exposure. In addition to the general microscopic findings, other features observed for included the proliferation of goblet cells producing mucus in the airways, acidification of neutral mucous granules in these goblet cells, the behavior of inflammatory cells such as alveolar macrophages, mast cells, and plasma cells, and the number of alveolar holes, known to be a primary indicator of early alveolar destruction. Focal anthracosis, acidified mucus in the goblet cells, and infiltration to the submucosa by inflammatory cells were observed in the lungs of the animals after 60 wk of exposure to polluted roadside air. However, these inflammatory changes were weak. No remarkable differences in the number of alveolar holes were noted between the two experimental groups. These findings suggest that the effects of roadside air on the respiratory tissue in rats may not be as severe as would be expected under these experimental conditions.

Air Pollutants↗
PubMed2002

Fenton and photo-Fenton oxidation of textile effluents.

The simultaneous use of Fenton reagent and irradiation for the treatment of textile wastewaters generated during a hydrogen peroxide bleaching process is investigated. The experimental conditions tested during this study provide the simultaneous occurrence of Fenton, Fenton-like and photo-Fenton reactions. The batch experimental results are assessed in terms of total organic carbon reduction. Identification of some of the chemical constituents of the effluent was performed by means of GC-MS. Other pollution related features of the initial effluent-like COD and color were also measured. The main parameters that govern the complex reactive system, i.e., light intensity, temperature, pH, Fe(II) and H2O2 initial concentrations have been studied. Concentrations of Fe(II) between 0 and 400 ppm, and H2O2 between 0 and 10,000 ppm were used. Temperatures above 25 degrees C and up to 70 degrees C show a beneficial effect on organic load reduction. A set of experiments was conducted under different light sources with the aim to ensure the efficiency of using solar light irradiation. The combination of Fenton, Fenton-like and photon-Fenton reactions has been proved to be highly effective for the treatment of such a type of wastewaters, and several advantages for the technique application arise from the study.

Environmental Monitoring↗
PubMedDate not supplied

[The dynamics of the fungal mycelial content in the soils of stationary posts in a 30-kilometer zone around the Chernobyl Atomic Electric Power Station].

The paper deals with mycobiota of radionuclide-polluted soils of seven stationary posts in the 30-kilometer zone of the Chernobyl NPP and one in the vicinities of Kiev (Feofaniia). The lengths of light-and dark-coloured fungal mycelium were determined in the soil under study by the method of membrane filters for 1987-1989. Data obtained have been analyzed with the account of the radioactivity level of the soil samples, season and depth of the sampling horizon. The dynamics of mycelium content in soils has been traced which evidences for its seasonal changes and prevalence of dark-pigmented mycelium at the beginning which then was changed by predominance of light-coloured mycelium. It is supposed that radioactive contamination of soil is one of considerable components of the whole complex of ecological factors which determine the dynamics of fungal mycelium content in soil.

Accidents↗
PubMedDate not supplied

Air pollution and brain damage.

Exposure to complex mixtures of air pollutants produces inflammation in the upper and lower respiratory tract. Because the nasal cavity is a common portal of entry, respiratory and olfactory epithelia are vulnerable targets for toxicological damage. This study has evaluated, by light and electron microscopy and immunohistochemical expression of nuclear factor-kappa beta (NF-kappaB) and inducible nitric oxide synthase (iNOS), the olfactory and respiratory nasal mucosae, olfactory bulb, and cortical and subcortical structures from 32 healthy mongrel canine residents in Southwest Metropolitan Mexico City (SWMMC), a highly polluted urban region. Findings were compared to those in 8 dogs from Tlaxcala, a less polluted, control city. In SWMMC dogs, expression of nuclear neuronal NF-kappaB and iNOS in cortical endothelial cells occurred at ages 2 and 4 weeks; subsequent damage included alterations of the blood-brain barrier (BBB), degenerating cortical neurons, apoptotic glial white matter cells, deposition of apolipoprotein E (apoE)-positive lipid droplets in smooth muscle cells and pericytes, nonneuritic plaques, and neurofibrillary tangles. Persistent pulmonary inflammation and deteriorating olfactory and respiratory barriers may play a role in the neuropathology observed in the brains of these highly exposed canines. Neurodegenerative disorders such as Alzheimer's may begin early in life with air pollutants playing a crucial role.

Air Pollutants↗
PubMed1975

Prevalence of chronic bronchitis in an industrial population in North India.

A survey for the prevalence of chronic bronchitis in an industrial population in North India is reported. The prevalence of chronic bronchitis is 12.5 percent in 473 subjects between the ages of 17 and 64 years. The prevalence rate of chronic bronchitis is comparable to that observed in areas of low community air pollution in Europe and North America. There is no age-related rise in the frequency of respiratory symptoms. The consumption of tobacco in these subjects is low and is comparable to tobacco consumption of light smokers. The prevalence of chronic bronchitis in smokers is five times the prevalence in non-smokers and is similar to the values reported for light smokers in other surveys. These observations suggest that cigarette smoking is associated with the development of chronic bronchitis, and the differences in the prevalence rate of chronic bronchitis between this survey and other surveys conducted in Europe and North America are mainly due to differences in smoking habits. Air pollution has a minor effect only and ethnic differences do not appear to play any part. Forced expired volume in one second shows a negative correlation with age. It is lower in asymptomatic smokers than in non-smokers and is lower in chronic bronchitis than in controls.

Adolescent↗
PubMed2005

Influence of pre-treatment step on PAHs analyses in contaminated soils.

There is no specific standardization for the pre-treatment of a soil sample for PAHs analyses. The ISO/FDIS 14507 method for soil quality gives a guidance for sample pre-treatment before measurement of organic contaminants in soil. It refers to cryogenic crushing which is not so easy to carry out. So, analysts lead to develop in house methods which can be very different from a laboratory to another and can involve deviations in the pollution quantification. This study has explored different ways of drying, grinding and sieving in order to determine the influence of the soil sample handling on the measured pollutant concentration. It appears that the influence of pre-treatment depends on the soil nature and on the PAHs distribution. As a conclusion, it is advised "light" drying ways like air drying or drying at 40 degrees C in a drying oven instead of more "drastic" ways (freeze-drying, cryogenic crushing) which can induce some losses. Crushing and sieving are also recommended for more reproducible measures.

Environmental Monitoring↗
PubMed1991

Urban and rural factors in the aetiology of cancer.

The incidence of cancer, or the mortality attributed to it, has been compared in urban and rural residents in 13 populations. In each case, the incidence (or mortality) has been higher in the urban areas in each sex, the ratios varying from a minimum of 1.03 to 1 in men in Japan to 1.63 to 1 in men in Denmark. Examination of 26 separate types of cancer showed that 23 tended to be more common in towns, 1 (myeloma) to be evenly distributed, and 2 (cancers of the lip and eye) to be more common in the countryside. The urban excess was greatest for cancers of the bladder, larynx, liver, lung, mouth and pharynx, and oesophagus, and least for leukaemia and non-Hodgkin's lymphoma. It is concluded that differences in personal behaviour (cigarette smoking, alcohol consumption, sexual promiscuity, exposure to ultraviolet light, type of diet, and family size) are the principal factors responsible for the urban excess. Other factors include general atmospheric pollution, occupational hazards, genetic differences in susceptibility, and artefacts of diagnosis and recording. The rural excess was marked for cancer of the lip in both sexes, but less marked and clearly evident only in men for cancer of the eye. Three-quarters of eye cancers are melanomas and the excess incidence in rural areas provides some weak support for the idea that exposure to sunlight contributes to the production of the disease.

Denmark↗
PubMed2006

Monitoring the photochemical degradation of triclosan in wastewater by UV light and sunlight using solid-phase microextraction.

Photo solid-phase microextraction (photo-SPME) is applied for the first time to study the photochemical behavior of an emerging pollutant, triclosan, in real contaminated wastewater samples using a solar simulator. In this study, water samples are extracted by SPME and then, the fiber coating is irradiated for a selected time. This on-fiber procedure, so-called photo-SPME, followed by gas chromatography-mass spectrometry makes it possible to study photodegradation kinetics and the generation of byproducts. Several photoproducts were identified in the real samples including the 2,8-dichlorodibenzo-p-dioxin, dichlorophenols and a compound tentatively identified as other DCDD congener or a dichlorohydroxydibenzofuran. Accordingly, it was possible to postulate main photodegradation mechanisms. Photo-SPME demonstrated slower kinetics in wastewater than in spiked ultrapure water probably due to the presence of dissolved organic matter. This technique was extensively compared with conventional aqueous photodegradation showing high similarity. The influence of pH on the triclosan photolysis and on the triclosan-dioxin conversion was also investigated in wastewater. Photodegradation of triclosan and formation of 2,8-DCDD occurred independently of sample pH. This study represents an advance in the use of photo-SPME to understand the photochemical fate of environmental organic pollutants and demonstrates its clear advantages with real samples.

Chromatography, Ion Exchange↗
PubMed2003

Oxidation of explosives by Fenton and photo-Fenton processes.

In this study, the Fenton process was used to explore the possibility of treating explosives, namely 2,4,6-trinitrophenol (PA), ammonium picronitrate (AP), 2,4-dinitrotoluene (DNT), methyl-2,4,6-trinitrophenylnitramine (Tetryl) and 2,4,6-Trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX). The photo-Fenton process was also conducted to compare its oxidation efficiency with the Fenton process. The inhibition of hydroxyl radical and theory of crystal field stabilization energy were introduced in this study. Results show that oxidation efficiencies in Fenton system are in the following sequence: DNT > PA > AP > TNT > Tetryl > RDX > HMX. The degradation of the explosives obeys a pseudo-first-order behavior, and possible decomposing mechanisms are also discussed. For all explosives, the oxidation rates significantly increased with increasing the concentration of Fe(II), as well as illumination with UV light.

Environmental Pollution↗
PubMed2003

Optical and chemical characteristics of the atmospheric aerosol in four towns in southern Poland.

The absorption coefficient a(p) [m(-1)] as well as the mass absorption coefficient sigma(p) [m(2)/g] has been estimated for PM10 and PM2.5 in four towns located in southern Poland, based on the assumption that the reflectance of aerosol-laden filters is a good proxy for the absorptivity of aerosols. The optical properties of the airborne particles were also compared with their surface composition obtained by photoelectron spectroscopy (XPS). It was found that coarse particles, which constituted 20-30% of PM10, exhibited insignificant contribution to the absorption. The most absorptive aerosols were found in the towns located in Upper Silesia, a highly industrialized area. This reflects both the relative content of carbon in PM2.5 and the mass concentration of the fine mode. It was found that oxides and sulfates play an important role in promoting the reflectance of light from aerosols in the winter. These results support the suggestion that the revision of existing air quality standards for particulate pollution is needed.

Journal Article↗