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At least 721 records · Page 40Linked to original sources
PubMed2000

Alteration of bioluminescence in Amphipholis squamata (Ophiuroidea: Echinodermata) by heavy metals contamination: a field study.

The ophiuroid Amphipholis squamata (Echinodermata) is a bioluminescent species whose light production varies with physico-chemical parameters of the medium. Individuals collected in the bay of Portman along a gradient of heavy metal contamination show different patterns of light production: the ones from the highest contaminated area showing a bioluminescence weaker and slower than those from the lowest contaminated area. Individuals that were transferred for 3 days from the lowest to the highest contaminated area displayed a light production that became weaker and slower. It is suggested that the decrease of the bioluminescent capability due to heavy metal pollution could indirectly affect the ophiuroid ecological success (bioluminescence is associated with defense functions in ophiuroids.

Animals↗
PubMed2003

Separation of fine particulate matter emitted from gasoline and diesel vehicles using chemical mass balancing techniques.

Samples of fine particulate matter were collected in a roadway tunnel near Houston, TX over a period of 4 days during two separate sampling periods: one sampling period from 1200 to 1400 local time and another sampling period from 1600 to 1800 local time. During the two sampling periods, the tunnel traffic contained roughly equivalent numbers of heavy-duty diesel trucks. However, during the late afternoon sampling period, the tunnel contained twice as many light-duty gasoline-powered vehicles. The effect of this shift in the vehicle fleet affects the overall emission index (grams pollutant emitted per kilogram carbon in fuel) for fine particles and fine particulate elemental carbon. Additionally, this shift in the fraction of diesel vehicles in the tunnel is used to determine if the chemical mass balancing techniques used to track emissions from gasoline-powered and diesel-powered emissions accurately separates these two emission categories. The results show that the chemical mass balancing calculations apportion roughly equal amounts of the particulate matter measured to diesel vehicles between the two periods and attribute almost twice as much particulate matter in the late afternoon sampling period to gasoline vehicles. Both of these results are consistent with the traffic volume of gasoline and diesel vehicles in the tunnel in the two separate periods and validate the ability for chemical mass balancing techniques to separate these two primary sources of fine particles.

Air Pollutants↗
PubMed1979

Benzene exposure in the rubber coating industry--a follow-up.

This paper is a follow-up on thirty-eight workers exposed from 1 to 24 years to average benzene concentrations generally between 5 and 50 ppm, but as high as 90 (peak of 140) in the case of one worker. One individual was diagnosed as suffering from mild benzene poisoning and a small number of workers in the group had blood changes considered abnormal, but blood dyscrasia or leukemia has not developed in 13 years after benzene use was terminated in 1964. The population studied was small, but the data, nevertheless, would appear to support the former ACGIH TLV of 25 ppm. One case of mild benzene poisoning reported from benzene exposures of the order of 40 ppm suggests, however, that the margin of safety may be small. The current ACGIH TLV of 10 ppm seems reasonable in the light of our findings.

Air Pollutants↗
PubMed1986

Oculotoxicities of systemically administered drugs.

There have been many drugs reported to cause oculotoxic responses after their systemic administration. The severity of these toxicities range from minor ocular inconvenience to permanent loss of vision. This paper reviews the current literature and attempts to suggest some probable factors involved in the development of oculotoxicities by systemic drugs. Various drug entry and exit pathways in the eye are presented and the role of some intraocular structures in the toxicity development is examined. The issues of melanin binding, genetic heterogeneity, photosensitivity and environmental pollution are discussed.

Eye↗
PubMed1996

Olaquindox-induced airborne photoallergic contact dermatitis followed by transient or persistent light reactions in 15 pig breeders.

There have been no previous reports of photosensitivity following photoallergy to airborne olaquindox in a large group. 15 pig breeders, with photo-distributed dermatitis related to olaquindox dust, were investigated to study the nature, promoting factors, and course of this disease. Minimal erythema doses for UVA and UVB were established before photopatch testing and at intervals thereafter. All patients presented with olaquindox-induced photoallergy. In 14 cases, this was followed by prolonged increased sensitivity to UVA. 7 patients also displayed an increased sensitivity to UVB. 13 farmers came into contact with olaquindox in mineral feed (1000 mg/kg) and only 2 in final feed (50 mg/kg). 8 patients avoided further contact with olaquindox because of warnings in the media. Allergies and photoallergies to other occupational substances preceded or followed olaquindox (photo)allergy. Because of their increased sensitivity to light, most of these farmers used sunscreens, and 2 of them developed (photo)allergy to UV-absorbers. As a result of our studies, we recommend photopatch testing for olaquindox in pig breeders with photo-distributed dermatitis. This would enable the early recognition of photoallergy to olaquindox and the prevention of persistent light reaction.

Adult↗
PubMed1999

Indoor air quality and the law in Singapore.

With the greater use of air-conditioned offices in Singapore, achieving good indoor air quality has become an important issue. The laws that impose duties upon designers and contractors with respect to the design and construction of air-conditioning and mechanical ventilation (ACMV) systems are set out in the Building Control Regulations and the Singapore Standard Code of Practice for Mechanical Ventilation and Air-conditioning in Buildings (hereinafter "SS CP 13:1980"). ACMV maintenance is governed by the Environmental Public Health Act, the Building and Common Property (Maintenance and Management) Act, and the Land Titles (Strata) Act, as well as by lease or tenancy agreements. Designers, contractors, developers, building owners and management corporations may also be liable to the workers, occupants and other premises users for indoor air quality (IAQ)-related injuries under the general principles of contract and tort. Recently, the Guidelines for Good Indoor Air Quality in Office Premises was issued by the Ministry of Environment to complement SS CP 13:1980 toward improving the indoor air quality of air-conditioned office premises. Although the Guidelines have no statutory effect, they may be adopted as contractual requirements in construction, lease and maintenance contracts. They may also be used to determine the relevant standard of duty of care required to discharge tortious liability. This paper looks at the existing laws and rules affecting the design, construction and maintenance of air-conditioned offices in light of Part III of the Ministry's Guidelines.

Air Conditioning↗
PubMed2006

Disturbance of human immunohomeostasis by environmental pollution and alcohol consumption.

Environmental pollution and consumption of alcohol evoke various immunomodulations promoting the progress of different pathologies. The purpose of this study was to evaluate the influence of alcohol consumption intensity on the immune system functions of humans living in ecologically different regions, i.e. in a district polluted with industrial siftings (Trakai, n = 270) and in a relatively clean district (Sirvintos, n = 250). In the Trakai cohort 96% and in Sirvintos group 89% of persons consumed alcohol. With regard to alcohol consumption habits the immunohaematological indices were investigated in the following four groups: abstinents, light alcohol users, moderate alcohol users and alcohol abusers. We determined the compensatory mechanisms of immune system functions of moderate alcohol users and alcohol abusers in comparison with abstinents in the relatively clean Sirvintos district. In the Trakai district polluted with industrial siftings such compensatory reactions where not found. Thus, damage to the immune system functions is not only an endogenous risk factor for many diseases, but also an indicator of organism injury. This investigation stated, that immunity disturbance in humans depends on alcohol consumption intensity and place of residence.

Adult↗
PubMedDate not supplied

[Persistent dyschromic erythema].

INTRODUCTION: Erythema dyschromicum perstans (ashy dermatosis) is a very rare skin disease included in the group of acquired, idiopathic hypermelanosis, with development of blue-gray macules. This disease appears more frequently in dark coloured persons, especially women in the first and second life decade. CASE REPORT: A male patient, 42 years of age, was admitted to Clinic of Dermatovenereology in Novi Sad due to appearance of slightly pruriginous, brown-reddish macules on the trunk, upper and lower extremities, without affecting the skin of the face, scalp, palm soles and visible mucous membranes. Later, the color of the macules changed into blue-gray and new lesions appeared in axilla and flexor side of the big joints, with active, erythematous and thin raised borders. Laboratory findings showed no abnormalities; antinuclear antibodies were negative. Histopathological examination of the skin specimens (which were taken from two different places) showed vacuolar degeneration of the basal cell layer, numerous pigmentophages in papillary dermis and presence of lymphohistiocytic infiltrate in dermis. No history of drug intake or exposure to UV light was established. DISCUSSION: Ashy dermatosis is included in the group of hypermelanosis of unknown origin. As possible etiological factors we can mention ingestion of ammonium nitrate, environmental pollution, hypersensitivity to cobalt chloride and postinflammatory pigmentation. Clinical characteristics: occurrence of blue-gray and gray macules on the trunk, face, neck and extremities (absence on the palms, soles, visible mucous membranes, scalp and nails). In the active phase of the disease, these macules are surrounded by erythematous and thin, raised borders. The lesions are mostly permanent. Due to clinical, histopathological, immunofluorescent and electron microscopy established similarities with lichen planus, it is considered that ashy dermatosis is a variant of lichen planus. Absence of previous drug intake, exposure to UV light, absence of the antinuclear antibodies, clinical picture and histological findings confirm the diagnosis of erythema dyschromicum perstans. CONCLUSION: This case of ashy dermatosis shows that there is a need for differential diagnosis of acquired skin pigmentations, because this dermatosis must also be taken into consideration.

Adult↗
PubMed1975

Experimental studies on human health effects of air pollutants. III. Two-hour exposure to ozone alone and in combination with other pollutant gases.

Adult male volunteers were exposed to ozone (O3) at 0.25, 0.37, or 0.50 ppm, and to O3 in combination with nitrogen dioxide (NO2) and carbon monoxide (CO), with secondary stresses of heat, intermittent light exercise, and repeated exposure. Few important physiological changes, and only mild symptoms, were found with 0.25 ppm O3, with 0.25 ppm 03 plus 0.30 ppm NO2, or when 30 ppm CO was added to the latter mixture. With 0.37 ppm O3, more symptoms were present and some subjects developed definite decreases in pulmonary function. With 0.50 ppm O3, most subjects had symptoms and about half showed substantial pulmonary function decrement. In reactive subjects exposed on two successive days, changes were usually greater the second day, indicating that effects of successive exposures were cumulative.

Adult↗
PubMed2004

Inactivation of Escherichia coli by photochemical reaction of ferrioxalate at slightly acidic and near-neutral pHs.

Fenton chemistry, which is known to play an effective role in degrading toxic chemicals, is difficult to apply to disinfection in water treatment, since its reaction is effective only at the acidic pH of 3. The presence of oxalate ions and UV-visible light, which is known as a photoferrioxalate system, allows the Fe(III) to be dissolved at slightly acidic and near-neutral pHs and maintains the catalytic reaction of iron. This study indicates that the main oxidizing species in the photoferrioxalate system responsible for microorganism inactivation is OH radical. Escherichia coli was used as an indicator microorganism. The CT value (OH radical concentration x contact time; used to indicate the effect of the combination of the concentration of the disinfectant and the contact time on inactivation) for a 2-log inactivation of E. coli was approximately 1.5 x 10(-5) mg/liter/min, which is approximately 2,700 times lower than that of ozone as estimated by the delayed Chick-Watson model. Since the light emitted by the black light blue lamp is similar to sunlight in the specific wavelength range of 300 to 420 nm, the photoferrioxalate system, which can have a dual function, treating water for both organic pollutants and microorganisms simultaneously, shows promise for the treatment of water or wastewater in remote or rural sites. However, the photoferrioxalate disinfection system is slower in inactivating microorganisms than conventional disinfectants are.

Disinfection↗
PubMed2005

Investigation of histopathological and cytogenetic effects on Lepomis gibbosus (Pisces: Perciformes) in the Cine stream (Aydin/Turkey) with determination of water pollution.

Water quality and the distribution of some heavy metals in three different organs of Lepomis gibbosus from the Cine Stream were studied. Also, histopathological changes in gill, liver, and muscle tissue were examined at light microscopical level. Micronucleus (MN) formation in fish erytrocytes, as an indicator of chromosomal damage, has been increasingly used to detect the genotoxic potential of environmental contaminants. The frequency of MN was examined from samples of fish from the Cine Stream and a control group. MN frequency was higher in fish samples caught from the Cine Stream than that in the control group. The chemicals ammonia, nitrite, nitrate, orthophosphate, and sulphate were determined as parameters that possibly affect the gill, liver, and muscle morphology. Zn was the most accumulated metal in tissues as well as in water. Maximum metal accumulation occurred in both liver and gills. For histopathological examinations, samples of gills, liver, and muscle tissues of L. gibbosus were studied by using light microscopy. In this study, a significant decrease in mean length of primary and secondary lamellae were observed. Moreover, cellular proliferation developed with secondary lamellae fusion, ballooning degenerations or club deformation of secondary lamellae, as well as distribution of necrotic, hyperplastic and clavate secondary lamellae. In the liver, altered staining, swollen and ruptured parenchymal cells, loss of cord structure, reduce of glycogen in hepatocytes, and vacuolar structure filled with cellular debris and many dark particles were seen. In muscle tissue, focal necrosis, cellular dissolution, and a decline or loss of striation in muscle fibres were found.

Animals↗
PubMed2007

Characterization of 2-methylglyceric acid oligomers in secondary organic aerosol formed from the photooxidation of isoprene using trimethylsilylation and gas chromatography/ion trap mass spectrometry.

In the present work, we have characterized in detail the chemical structures of secondary organic aerosol (SOA) components that were generated in a smog chamber and result from the photooxidation of isoprene under high-NO(x) conditions typical for a polluted atmosphere. Isoprene high-NO(x) SOA contains 2-methylglyceric acid (2-MG) and oligoester derivatives thereof. Trimethylsilylation, in combination with capillary gas chromatography (GC)/ion trap mass spectrometry (MS) and detailed interpretation of the MS data, allowed structural characterization the polar oxygenated compounds present in isoprene SOA up to 2-MG trimers. GC separation was achieved between 2-MG linear and branched dimers or trimers, as well as between the 2-MG linear dimer and isomeric mono-acetate derivatives thereof. The electron ionization (EI) spectra of the trimethylsilyl derivatives contain a wealth of structural information, including information about the molecular weight (MW), oligoester linkages, terminal carboxylic and hydroxymethyl groups, and esterification sites. Only part of this information can be achieved with a soft ionization technique such as electrospray (ESI) in combination with collision-induced dissociation (CID). The methane chemical ionization (CI) data were used to obtain supporting MW information. Interesting EI spectral differences were observed between the trimethylsilyl derivatives of 2-MG linear and branched dimers or trimers and between 2-MG linear dimer mono-acetate isomers.

Aerosols↗
PubMed1998

A new low-cost microbiotest with the Protozoan spirostomum teres: culture conditions and assessment of sensitivity of the ciliate to 14 pure chemicals.

This paper defines the culture conditions of the ciliate Spirostomum teres and assesses its sensitivity to some xenobiotics for the development of a new low-cost microbiotest. The model was selected for its ubiquitous distribution, large size for a unicellular species, easy culture in holoxenic medium, moderate generation time, and high sensitivity to pure toxicants. The influence of different culture waters, inocula of ciliates, food, temperature, light, and darkness on the growth of the ciliate population was tested. The shortest generation time (average 39 h) was obtained for cultures incubated at 25 degreesC in the dark with an inoculum of 4 ciliates per ml in 25 ml of Volvic mineral water containing 8 boiled wheat grains, when preincubated without ciliates for the previous week. Under these conditions, it was possible to obtain about 3000 ciliates/ml 3 weeks later. Acute toxicity tests (24-h LC50) were carried out for CuSO4, HgCl2, CdCl2, K2Cr2O7, ZnSO4, Pb(NO3)2, thiram, carbaryl, lindane, parathion, parathion methyl, paraoxon, 2, 4,6-trichlorophenol, and sodium pentachlorophenolate (Na-PCP). Very high sensitivity of the model to Hg2+, Cu2+, Cd2+, thiram, and Na-PCP was established. Comparison of its sensitivity with that of Microtox (current results), Daphnia Magna, Tetrahymena pyriformis, Colpidium campylum, and murine fibroblasts (data from literature) confirms the high sensitivity of the model, especially to heavy metals. Easy-to-perform, cost-effective, and sensitive bioassays using S. teres are suitable for risk assessment and early detection of toxicity in fresh water.

Animals↗