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PubMed1999

Adaptive responses in Chlamydomonas reinhardtii.

The photosynthetic single cellular alga Chlamydomonas reinhardtii has been used as a model organism to examine in detail the physiological, biochemical and molecular processes of photosynthesis, flagella synthesis and movement, mineral stress, interactions between nucleus, chloroplasts and mitochondria and other processes. In this review we summarize part of the current knowledge on adaptive responses in C. reinhardtii when it is exposed to oxidative stress and to changes in light intensity, concentration of minerals, herbicides and metals. The individual responses are linked in order to understand the response of the cell, which is continuously subjected to fluctuations, as a whole.

Adaptation, Physiological↗
PubMed2003

Changes in phototactic behavior of Daphnia magna clone C1 242 in response to copper, cadmium and pentachlorophenol.

In order to develop a sound biotechnique for monitoring water quality that builds on the previous experiments carried out in our laboratory, a specific D. magna clone C1 242 was used to study the effects of pollutants on phototactic behavior. In all experiments, the animals showed a stable and repeatable phototactic index approximated 0.2 in the presence and 0.4 in the absence of fish kairomones, which decreased significantly in response to pollutants. There existed no pollutant x fish kairomone interaction, indicating the changes in phototactic behavior of animals imposed by pollutants were independent of the presence of fish kairomones. The detection limits for changes in phototactic behavior of D. magna clone C1 242 are 0.04 mg/L for copper, 0.02 mg/L for cadmium, and 0.80 mg/L for PCP, respectively, quite lower than LC50 (48 h). The changes in phototactic behavior in presence to pollutants occurred quickly (3 h) compared to the period over whole acute toxicity tests. Therefore, D. magna clone C1 242 could be potentially used to monitor water quality. Moreover, the phototactic behavior did not decrease further in the pollutant mixtures employed in our experiments compared to individual pollutants, except in the Cd-PCP treatment. This fact suggests that the formation of water quality criteria must be based upon pollutant mixture tests.

Analysis of Variance↗
PubMed1987

[Demonstration of gram-negative bacteria and endotoxins in the air surrounding a sewage treatment plant: effect of contaminated aerosols on the health status of the staff].

Data on airborne gram-negative bacteria and endotoxin contamination in a sewage treatment plant are reported and compared with data from similar plants in Scandinavia. Respiratory, digestive, and cutaneous symptoms were investigated on the basis of medical files. The contamination levels which can be considered safe are discussed in the light of the actual exposure of workers.

Adult↗
PubMed1978

Morphometric and morphologic evaluation of pulmonary lesions in beagle dogs chronically exposed to high ambient levels of air pollutants.

Beagle dogs (104) comprising one control and seven treatment groups were exposed 16 hours daily for 68 months to filtered air, raw or photochemically reacted auto exhaust, oxides of sulfur or nitrogen, or their combinations. After a further 32 to 36 months in clean air, morphologic examination of lungs by light microscopy, scanning electron microscopy, and transmission electron microscopy revealed two important exposure-related lesions. They were enlargement of air spaces in proximal acinar regions, with and without increases in the number and size of interalveolar pores, and hyperplasia of nonciliated bronchiolar cells. Proximal enlargment of air spaces was most severe, both subjectively and morphometrically, in those dogs exposed to oxides of nitrogen, oxides of sulfur, or oxides of sulfur with photochemically reacted auto exhause. In contrast, hyperplasia of nonciliated bronchiolar cells was most severe in dogs exposed to raw auto exhaust alone or with oxides of sulfur. The air space enlargement and hyperplasia of bronchiolar epithelium correlated with functional impairment reported as occurring in these dogs. Foci of ciliary loss with and without squamous metaplasia were occasionally observed in trachea and bronchi. The observations indicate that enlargement of proximal acinar air spaces with some loss of interalveolar septa can develop in the absence of alveolar fenestrations. The persistnt nature of bronchiolar cell proliferations in such circumstances was also demonstrated. Two major toxicologic implications are (1) the production of permanent lung damage by much lower concentrations of pollutants than previously reported and (2) the apparent lack of additive or synergistic effects between oxidant gases and sulfur oxides.

Air Pollutants↗
PubMed2002

Ethical and economic issues in the use of zero-emission vehicles as a component of an air-pollution mitigation strategy.

The air pollution generated by motor vehicles and by static sources is, in certain geographic areas, a very serious problem, a problem that exists because of a failure of the marketplace. To address this marketplace failure, the State of California has mandated that by 2003, 10% of the Light-Duty Vehicle Fleet (LDV) be composed of Zero-Emission Vehicles (ZEVs). However, the policy-making process that was utilized to generate the ZEV mandate was problematic and the resulting ZEV mandate is economically unsound. Moreover, an ethical analysis, based primarily upon the work of John Rawls, suggests that implementation of the California ZEV mandate is--in spite of the wide latitude that ought to be given to policy decision makers--unethical. A more ethical and economically efficient approach to the pollution caused by marketplace failure is one that relies on market incentives and thereby achieves the desired improvement in air quality by appealing both to the self-interest of motorists and to those businesses that are directly or indirectly involved with the automobile industry. Such an approach would take better advantage of the creative forces of the market and improvements in technology over time and avoid the infringements on individual liberty and fairness embodied in the ZEV mandate.

Air Pollution↗
PubMed2004

Using factor analysis to attribute health impacts to particulate pollution sources.

Laden et al. (2000) recently reported results of applying factor analysis to data taken in six cities from 1979 to 1988, identifying airborne particle sources potentially affecting daily mortality. These authors sought relationships between source groups and risk measures using source tracer elements, Se (coal combustion), Pb (light-duty motor vehicle sources), and Si (crustal--soil dispersion). Combined data analyses of this kind may overlook the complexity of source contributions, which have common tracer elements. In one of the cities, Boston, for example, the authors found coal combustion was an important source of mortality risk. For the city of Boston, the authors attribute coal combustion largely to distant upwind regional sources. The emphasis on coal combustion is confounded by the presence of major local sources of residual oil combustion, which contribute V, Se, and S (sulfur as sulfate) to the source apportionment. Evaluation of the source identification using single-element tracer analysis indicates that the detailed chemical composition or profile of major local sources needs to be taken into account in these investigations to minimize misclassification of airborne particle sources with potential adverse health effects.

Air Pollutants↗
PubMed1991

Alteration of primate ovary surface epithelium by exposure to hexachlorobenzene: a quantitative study.

Hexachlorobenzene (HCB) is a fungicide and a pollutant of increasing concern in industrialized regions of the world. Reproductive failure is one of the effects of HCB upon mammals. Alteration of cell shape in the ovary surface epithelium (OSE) of Cynomolgus monkeys following oral administration of HCB was observed in this study. At the lowest dose used, 0.1 mg/kg body weight, a dosage that is associated with follicular degeneration, HCB caused quantifiable changes in length-to-width ratios of OSE. Measurement of cell shape by light microscopy offers a reliable indication of OSE changes induced by HCB.

Animals↗
PubMed2004

Effects of lindane on the photosynthetic apparatus of the cyanobacterium Anabaena: fluorescence induction studies and immunolocalization of ferredoxin-NADP+ reductase.

INTENTION, GOAL, SCOPE, BACKGROUND: Cyanobacteria have the natural ability to degrade moderate amounts of organic pollutants. However, when pollutant concentration exceeds the level of tolerance, bleaching of the cells and death occur within 24 hours. Under stress conditions, cyanobacterial response includes the short-term adaptation of the photosynthetic apparatus to light quality, named state transitions. Moreover, prolonged stresses produce changes in the functional organization of phycobilisomes and in the core-complexes of both photosystems, which can result in large changes in the PS II fluorescence yield. The localization of ferredoxin-NADP+ reductase (FNR) at the ends of some peripheral rods of the cyanobacterial phycobilisomes, makes this protein a useful marker to check phycobilisome integrity. OBJECTIVE: The goal of this work is to improve the knowledge of the mechanism of action of a very potent pesticide, lindane (gamma-hexaclorociclohexane), in the cyanobacterium Anabaena sp., which can be considered a potential candidate for bioremediation of pesticides. We have studied the effect of lindane on the photosynthetic apparatus of Anabaena using fluorescence induction studies. As ferredoxin-NADP+ reductase plays a key role in the response to oxidative stress in several systems, changes in synthesis, degradation and activity of FNR were analyzed. Immunolocalization of this enzyme was used as a marker of phycobilisome integrity. The knowledge of the changes caused by lindane in the photosynthetic apparatus is essential for rational further design of genetically-modified cyanobacteria with improved biorremediation abilities. METHODS: Polyphasic chlorophyll a fluorescence rise measurements (OJIP) have been used to evaluate the vitality and stress adaptation of the nitrogen-fixing cyanobacterium Anabaena PCC 7119 in the presence of increasing concentrations of lindane. Effects of the pesticide on the ultrastructure have been investigated by electron microscopy, and FNR has been used as a marker of phycobilisome integrity. RESULTS AND DISCUSSION: Cultures of Anabaena sp. treated with moderate amounts of lindane showed a decrease in growth rate followed by a recovery after 72 hours of pesticide treatment. Concentrations of lindane below 5 ppm increased the photosynthetic performance and activity of the cells. Higher amounts of pesticide caused a decrease in these activities which seems to be due to a non-competitive inhibition of PS II. Active PS II units are converted into non-QA reducing, so called heat sink centers. Specific activity and amount of FNR in lindane-treated cells were similar to the values measured in control cultures. Release of FNR from the thylakoid after 48 hours of exposure to 5 ppm of lindane towards the cytoplasm was detected by immunogold labeling and electron microscopy. CONCLUSIONS: From these results, we conclude that the photosynthetic performance and activity of the cells are slightly increased in the presence of lindane up to 5 ppm. Moreover, in those conditions, lindane did not produce significant changes in the synthesis, degradation or activity of FNR. The high capability of Anabaena to tolerate lindane makes this cyanobacterium a good candidate for phytoremediation of polluted areas. RECOMMENDATION AND OUTLOOK: The results of this study show that cultures of Anabaena PCC 7119 tolerate lindane up to 5 ppm, without significant changes in the photosynthetic vitality index of the cells. However, a slight increase in phycobiliprotein synthesis is observed, which is related to total protein content. This change might be due to degradation of proteins less stable than phycobiliproteins. An identification of the proteins with altered expression pattern in the presence of the pesticide remains the subject of further work and will provide valuable information for the preparation of strains which are highly tolerant to lindane.

Anabaena↗
PubMed1994

Sunlight, vitamin D, and ovarian cancer mortality rates in US women.

BACKGROUND: In general, ovarian cancer incidence and mortality is higher in northern than southern latitudes. This ecologic study tests the hypothesis that vitamin D produced in the skin from sunlight exposure may be associated with a protective action in ovarian cancer mortality. METHODS: The association between average annual sunlight energy and age-specific ovarian cancer mortality rates in counties containing the 100 largest US cities was evaluated for 1979-1988. Simple linear regression was performed by decade using sunlight and ozone as independent variables and ovarian cancer rates as the dependent variable. Multiple regression was used to adjust for ozone and sulphur dioxide, since these atmospheric components may absorb ultraviolet light. RESULTS: Fatal ovarian cancer in these areas was inversely proportional to mean annual intensity of local sunlight in a univariate analysis (P = 0.0001), and in a regression adjusted for air pollution (P = 0.04). The association was also seen when restricted to 27 major urban areas of the US; however, probably due to a small sample size, this statistic did not reach significance. CONCLUSIONS: This ecologic study supports the hypothesis that sunlight may be a protective factor for ovarian cancer mortality.

Adult↗
PubMed2001

Anaerobes, aerobes and phototrophs. A winning team for wastewater management.

Current mainstream technologies for wastewater treatment, such as activated sludge and tertiary nutrient removal, are too costly to provide a satisfactory solution for the increasing wastewater problems in developing regions. Besides, these technologies do not allow for re-use of valuable energy and nutrients contained in the wastewater. In light of these limitations, it is important to reconsider the technology and strategic approaches in wastewater management. This paper introduces the "Cleaner Production" concept to sewage management, which combines two approaches: pollution prevention and re-use. Pollution prevention includes a shift towards low water use sanitation technology. The more concentrated wastewater, becomes more attractive for re-use oriented treatment schemes. A combination of anaerobic pre-treatment followed by macrophyte-covered stabilisation ponds is proposed for the effective recovery of energy and nutrients from sewage. By selecting optimal applications of the plant biomass and pond effluent, nutrients will end up as fish and crop protein. This contrasts favourably to tertiary nitrogen removal in activated sludge systems, which recycles ammonia through molecular nitrogen at the expense of energy and high costs. Macrophyte ponds are proposed as a key step in waste recycling, because these form the central unit of a recycling engine, driven by photosynthesis. The process is energy efficient, cost effective and applicable under a wide variety of rural and urban conditions.

Ammonia↗
PubMed1992

The lessons of life: keynote address to the nutrition and cancer conference.

Some 15 years ago there began to emerge a consensus among epidemiologists that diet might be responsible for 30-60% of cancers in the developed world, in the sense that it should be possible to reduce age-specific incidence rates by this amount by practicable dietary change. Within about 6 years it was also broadly agreed that the principal changes required to bring about this effect were a reduction in the consumption of fat; an increase in the consumption of fruit, green and yellow vegetables, dietary fiber, and some micronutrients; and possibly an improvement in the methods of food preservation. Very small effects, if any, were attributed to food additives and to the pollution of food by trace pesticides, which the public, who accepted much of the consensus advice, have increasingly regarded as important causes of risk. These past conclusions are reviewed in the light of increased knowledge of the etiology of cancer and the trends in its incidence. Contrary to common belief, the trends are broadly encouraging.

Age Factors↗
PubMed1997

Alveolar macrophage interaction with air pollution particulates.

We applied flow cytometric analysis to characterize the in vitro response of alveolar macrophages (AM) to air pollution particulates. Normal hamster AM were incubated with varying concentrations of residual oil fly ash (ROFA) or concentrated ambient air particulates (CAP). We found a dose-dependent increase in AM-associated right angle light scatter (RAS) after uptake of ROFA (e.g., mean channel number 149.4 +/- 6.5, 102.5 +/- 4.1, 75.8 +/- 3.5, and 61.0 +/- 4.6 at 200, 100, 50, and 25 mg/ml, respectively) or CAP. A role for scavenger-type receptors (SR) in AM uptake of components of ROFA and CAP was identified by marked inhibition of RAS increases in AM pretreated with the specific SR inhibitor polyinosinic acid. We combined measurement of particle uptake (RAS) with flow cytometric analysis of intracellular oxidation of dichlorofluorescin. Both ROFA and CAP caused a dose-related intracellular oxidant stress within AM, comparable to that seen with phorbol myristate acetate (PMA) (e.g., fold increase over control, 6.6 +/- 0.4, 3.6 +/- 0.4, 4.6 +/- 0.5, 200 mg/ml ROFA, 100 mg/ml ROFA, and 10(-7) M PMA, respectively). We conclude that flow cytometry of RAS increases provides a useful relative measurement of AM uptake of complex particulates within ROFA and CAP. Both ROFA and CAP cause substantial intracellular oxidant stress within AM, which may contribute to subsequent cell activation and production of proinflammatory mediators.

Air Pollutants↗
PubMedDate not supplied

[Morphologic and molecular-genetic characterization of lung cancer developing in people who have worked at nuclear facilities and who have lived in Russian territories polluted after the accident at the Chernobyl power plant].

Clinicomorphological analysis of 15 lung carcinomas of patients who had been exposed for a long time to the radiation after the Chernobyl accident was performed. The material consisted of 10 surgical and 5 autopsy cases and was studied at the light, electron microscopic and immunohistochemical level. There were 6 peripheral, 8 central carcinomas and one massive tumor. Fibrous areas with many dust particles were found in peripheral carcinomas. In central tumors chronic obstructive bronchitis with epithelial dysplasia and metaplasia was observed. Carcinoma was represented by various histologic types: small cell (4 cases), combined small cell with squamous differentiation (5 cases), adenocarcinoma (5 cases), adenosquamous type (1 case). Peculiar calcium deposits in both stroma and parenchyma were found in tumors with glandular differentiation. Morphogenesis of calcium microdeposits may be connected with dust radioactive particles elimination. Central carcinoma had, in the majority of cases, a neuroendocrine differentiation and can be related to some types of small cell carcinoma. Peripheral cancer was mostly of a glandular differentiation and was, as a rule, carcinoma in the scar. Lung carcinomas studied had peculiar molecular-genetic features: lack or low bcl-2 expression, low Ki-67 expression and a high degree of c-myc expression. Tumors were characterized by a low apoptosis index independently of a histologic type. Apoptosis was not complete: lack of apoptotic bodies phagocytosis this resulting in postapoptotic detritus formation.

Adult↗
PubMed2004

Construction of transformant reporters carrying fused genes using pcbC promoter of Pseudomonas sp DJ-12 for detection of aromatic pollutants.

Three reporter gene fusions were constructed by a transcriptional fusion method using the pcbC promoter of Pseudomonas sp. DJ-12, which can extensively degrade biphenyl and 4-chlorobiphenyl by meta-cleavage dioxygenase. The reporter genes used for the construction of the fusions were luc, luxCDABE and gfpuv. The reporter fusion plasmids were introduced into E. coli XL1-Blue, and the transformant reporters examined for the production of fluorescent light by exposure to aromatic compounds, such as biphenyl, 4-chlorobiphenyl, 4-hydroxybiphenyl, 2,3-dihydroxybiphenyl, catechol and 4-chlorocatechol. The reporter cells, carrying the respective gene fusions, responded well to the aromatics when exposed to a concentration of 0.1 mM for 10 min. In particular, the reporter cells carrying the pcbCp::luxCDABE gene fusion produced bioluminescence most extensively to the above mentioned aromatics. This means that the pcbCp::luxCDABE reporter gene fusion may be useful in bacterial biosensors for the detection of aromatic pollutants in the environment, and may also be valuable for examining the bioavailability of the inducing pollutants.

Artificial Gene Fusion↗
PubMed1996

A consensus approach to planetary protection requirements: recommendations for Mars lander missions.

Over the last several years, the nature of the surface conditions on the planet Mars, our knowledge of the growth capabilities of Earth organisms under extreme conditions, and future opportunities for Mars exploration have been under extensive review in the United States and elsewhere. As part of these examinations, in 1992 the US Space Studies Board made a series of recommendations to NASA on the requirements that should be implemented on future missions that will explore Mars. In particular, significant changes were recommended in the requirements for Mars landers, changes that significantly alleviated the burden of planetary protection implementation for these missions. In this paper we propose a resolution implementing this new set of recommendations, for adoption by COSPAR at its 30th meeting in Hamburg. We also discuss future directions and study areas for planetary protection, in light of changing plans for Mars exploration.

Consensus Statements as Topic↗
PubMed2006

Gas/particle partitioning and yield levels of polycyclic aromatic hydrocarbons and n-alkanes in the mainstream cigarette smoke of commercial cigarette brands.

The gas/particle partitioning of polycyclic aromatic hydrocarbons (PAHs) and n-alkanes was investigated in the mainstream smoke (MSS) from 59 commercial cigarette brands classified according to the existence of filter tip, the tar yield indicated on the packet, and the cigarette length and diameter, into 15 cigarette classes: non filter (NF), high (H), medium (M), light (L), super light (SL), ultra light (UL), one-tar yield (O), 100-mm long (H-100, L-100, SL-100, UL-100, O-100), and slim (SL-SLIM, UL-SLIM, O-SLIM). The gas/particle partitioning constant, Kp, was determined and its relationship with the subcooled liquid vapour pressure pL degrees of individual compounds was investigated. A good linear relationship was obtained for both chemical classes following the equation log Kp=mr log pL degrees+br. In all cigarette classes, PAHs were found to sorb more strongly on MSS particles than n-alkanes. Carcinogenic PAHs were detectable only in the total particulate matter (TPM) of MSS and their yields increased linearly with the TPM yield. However, when normalized against TPM, the yields of carcinogenic PAHs were quite similar in all cigarette classes with a slight drop from low tar- to high tar-yield brands suggesting probably lower biological activity per mg TPM for the latter. The nicotine-normalized PAH yields were also similar among the different cigarette classes suggesting that, if smokers adjust their smoking behavior to achieve a consistent nicotine intake, they will be exposed to an equivalent amount of carcinogenic PAHs regardless of whether they smoke full-flavored, light, or ultralight varieties.

Alkanes↗
PubMed1998

Genotoxicological monitoring of 175 subjects living in the green belts, inner town or near chemical industrial estates in Greater Budapest agglomeration, Hungary.

We studied the effects of chronic low dose exposure to environmental pollutants on the peripheral blood lymphocytes (PBL) of subjects living in the green belts and the inner town, and/or working in the surrounding of industrial estates of Greater Budapest agglomeration, Hungary. The effects of some biological (gender, age, hematocrit and white blood cell counts), lifestyle (smoking, drinking habits and residential areas), and seasonal confounding factors were also considered. PBLs of 175 Hungarian donors of Budapest agglomeration, i.e. 45 subjects living in the green belts without significant genotoxic exposure (C1), 43 donors living in the inner town (C2), and 87 individuals living and/or working near chemical industrial estates (C3), were analysed for structural and numeric chromosome aberrations (CA), sister-chromatid exchanges (SCE), cell proliferation indices (lectine stimulation, LI; and proliferation rate index, PRI), and UV-light-induced unscheduled DNA synthesis (UDS). Each subject was interviewed personally and also investigated clinically. The three populations were matched for age, smoking and drinking habits. We excluded all donors with acute infectious and/or chronic non-infectious diseases, and/or with exposure to any known chemical hazard. For C1s, the base line CA and SCE frequencies were 0.25% and 6.41 per mitosis, respectively; in C2, these frequencies were 0.48% and 6.07 per mitosis, respectively, and in C3, these data were 1.60% and 5.71 per mitosis, respectively. A significant increase of CA due to chromosome type acentric fragments was demonstrated in the donors living in the inner town (C2), compared to those living in the green belts (C1). In C3s, significant (p < 0.05) elevations were found in the frequencies of gaps, aberrant cells, total aberrations (excluding gaps), chromatid and chromosome type aberrations, and in UDS, compared to C1s. Results indicate an increased genotoxicologic risk in donors living and/or working in industrial areas. Gender-related differences in SCE frequencies were demonstrated in C2 and C3; in the latter smoking-induced changes in UDS were also found. Light drinking did not appear to influence the results.

Adult↗
PubMed2000

Occupational exposure and respiratory illness symptoms among textile industry workers in a developing country.

This study investigates the respiratory health profile of textile mill workers in Bangladesh, aiming to develop workers' awareness and public attention, and to ensure a proper implementation of health and safety measures. Forced vital capacity was measured by peak expiratory flow rate instrument among 210 subjects. The personal history, the occupational history, and the state of health were also determined using a questionnaire and checklists. The subjects who had a considerably low peak expiratory flow rate (< 290 liters/min), and had symptoms of chronic respiratory illness, underwent X-ray examination. A statistically significant low peak expiratory flow rate was identified among 52.9 percent of workers. Among them, 42.9 percent had symptoms of cough with or without phlegm; 5.7 percent had a history of chronic bronchitis and/or asthma, and 4.3 percent experienced chest tightness or breathlessness. This study showed a high degree (p < .001) of respiratory-related illness symptoms present among the workers in the blow/card rooms and the workers in the spinning section. Irrespective of variation of age as well as work pattern, non-smokers were less likely to be affected. Whether worker were occupationally exposed to other incidences was also investigated. The results of these investigations are presented and the findings discussed in light of other studies carried among similar occupational groups.

Adolescent↗