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At least 55 records · Page 3Linked to original sources
PubMed2004

Phytoextraction of heavy metals by canola (Brassica napus) and radish (Raphanus sativus) grown on multicontaminated soil.

Phytoextraction can provide an effective in situ technique for removing heavy metals from polluted soils. The experiment reported in this paper was undertaken to study the basic potential of phytoextraction of Brassica napus (canola) and Raphanus sativus (radish) grown on a multi-metal contaminated soil in the framework of a pot-experiment. Chlorophyll contents and gas exchanges were measured during the experiment; the heavy metal phytoextraction efficiency of canola and radish were also determined and the phytoextraction coefficient for each metal calculated. Data indicated that both species are moderately tolerant to heavy metals and that radish is more so than canola. These species showed relatively low phytoremediation potential of multicontaminated soils. They could possibly be used with success in marginally polluted soils where their growth would not be impaired and the extraction of heavy metals could be maintained at satisfying levels.

Brassica napus↗
PubMed1990

A study of work conditions on board fishing vessels in the far-eastern region.

The authors present the results of investigations conducted on board sea-going fishing vessels during long-lasting voyage. They covered common dangerous occupational exposures to noise vibration, lighting, microclimate, air pollution in the work zone and the ship construction. The negative conditions these concerning were described.

Air Pollutants, Occupational↗
PubMed2005

Visible light induced photodegradation of organic pollutants on nitrogen and fluorine co-doped TiO2 photocatalyst.

The nitrogen and fluorine co-doped TiO2 polycrystalline powder was synthesized by calcinations of the hydrolysis product of tetrabutyl titanate with ammonium fluoride. Nitrogen and fluorine co-doping causes the absorption edge of TiO2 to shift to a lower energy region. The photocatalytic activity of co-doped TiO2 with anatase phases was found to be 2.4 times higher than that of the commercial TiO2 photocatalyst Degussa P25 for phenol decomposition under visible light irradiation. The co-doped TiO2 powders only contain anatase phases even at 1000 degrees C. Apparently, ammonium fluoride added retarded phase transformation of the TiO2 powders from anatase to rutile. The substitutional fluorine and interstitial nitrogen atoms in co-doped TiO2 polycrystalline powder were responsible for the vis light response and caused the absorption edge of TiO2 to shift to a lower energy region.

Absorption↗
PubMed2004

Visible-light-assisted degradation of dye pollutants over Fe(III)-loaded resin in the presence of H2O2 at neutral pH values.

A novel catalyst was synthesized by direct exchange of ferric ions onto a cationic resin (Amberlite IRA200). Upon visible light irradiation (lambda > 420 nm) in the presence of H2O2, this catalyst was found to be highly effective for the degradation of nonbiodegradable cationic dyes, Malachite green, Rhodamine B, and Methylene blue, even at neutral pH values. It was also easy to separate from the degraded solution. By total organic carbon, FT-IR, and GC-MS analysis, the degradation process of Malachite green was shown to proceed with demethylation and phenyl ring openings into CO2 and small molecular compounds. EPR studies revealed that *OH radicals, other than *OOH/O2*-, were involved as the active species. A possible reaction mechanism is proposed on the basis of all the information obtained under various experimental conditions.

Catalysis↗
PubMed1989

[Studies of the effect of environmental factors on the visual system (based on the examination of workers at a precision instrument factory)].

The studies involved 254 workers of a Precise Devices Plant. The impact of working conditions (chemical pollutants and lighting) on the sight organ was examined. In the test group a considerable percentage (29.5%) of chronic conjunctivitis was found. The disease results from a long-lasting exposure to dusts of various origin, as well as from improper lighting. The posttraumatic and post-inflammatory impairments of the sight organ, diagnosed by ophthalmological examinations, were not of occupational origin.

Adult↗
PubMed1997

Ozone, suspended particulates, and daily mortality in Mexico City.

To investigate acute, irreversible effects of exposure to ozone and other air pollutants, the authors examined daily death counts in relation to air pollution levels in Mexico City during 1990-1992. When considered singly in Poisson regression models accounting for periodic effects, the rate ratio for total mortality associated with a 100-ppb increment in 1-hour maximum ozone concentration was 1.024 (95% confidence interval (CI) 1.011-1.039). Measures of average ozone concentration were somewhat more strongly related to mortality. The rate ratio was 1.024 (95% CI 0.984-1.062) per 100 ppb for sulfur dioxide and 1.050 (95% CI 1.030-1.067) per 100 micrograms/m3 for total suspended particulates. However, when all three pollutants were considered simultaneously, only total suspended particulates remained associated with mortality, indicating excess mortality of 6% per 100 micrograms/m3 (rate ratio = 1.058, 95% CI 1.033-1.083), consistent with observations in other cities in the United States and Europe. The authors found no independent effect of ozone, but it is difficult to attribute observed effects to a single pollutant in light of the complexity and variability of the mixture to which people are exposed. Nevertheless, particulate matter may be a useful indicator of the risk associated with ambient air pollution.

Adolescent↗
PubMed2000

Analysis and simulation of wintertime light scattering by the urban aerosol in Dallas-Fort Worth.

Wintertime atmospheric light scattering in Dallas, TX, was estimated through the use of aerosol models. Input data for the aerosol models were provided by measurements of aerosol chemistry, physical particle size distributions, and distributions of particulate sulfur by particle size, and by predictions by an atmospheric simulation model. Light scattering measurements provided a basis for testing the aerosol models. The SCAPE thermodynamic equilibrium model was used to estimate the amount of liquid water associated with particles and the ELSIE Mie scattering model was applied to estimate the resulting light scattering. The calculations were based on aerosol properties measured in Dallas during December 1994 and February 1995, and changes in scattering due to hypothetical changes in the aerosol were predicted. The predicted light scattering was compared to scattering measured by an Optec nephelometer; agreement was within 20% in every case.

Aerosols↗
PubMed2005

The effect of ozone on the yellowing process of magnesium-deficient clonal Norway spruce grown under defined conditions.

During two vegetation periods, young clonal spruce trees (Picea abies (L.) Karst.) with sufficient and poor magnesium (Mg) supply were exposed in the environmental chambers of the GSF phytotron to three levels of ozone (daily means: 18-22, 88-130, and 135-190 microg m(-3); 10% reduction at night). Previous year's needles were examined at 4-week intervals with respect to their contents of Mg, Ca, K, Mn, N, P, and chlorophyll (Chl), various parameters of Chl fluorescence, and the stability of the isolated light-harvesting Chl-a/b-protein complex LHC II. The needles of the two nutrition variants contained more than 0.53 or less than 0.27mg Mg g(-1) needle dry matter, respectively. The ratio of variable to maximal Chl-a fluorescence of the dark-adapted needles, Fv/Fm, and the photoinhibitory quenching of Fv after light treatment, SVi.v, were affected by the Mg content of the needles rather than the ozone levels. Changes of the Chl content and the behavior of the LHC II allowed differentiating between a slow process of needle yellowing occurring under Mg deficiency only, and a rapid process of needle yellowing occurring under the combined action of Mg deficiency and ozone pollution. Only the rapid yellowing process was accompanied by destabilization of the LHC II, and the degree of destabilization was correlated with the ozone concentration present in the days before sampling. The results are consistent with observations obtained at a research site in the Central Black Forest (J Plant Physiol 161 (2004) 423).

Air Pollutants↗
PubMed2003

[Distribution of microcystin-LR and anatoxin-A and their influence factors in Dianshan Lake during summer and autumn].

Six different sampling locations in Dianshan Lake were selected to study the distributions of algaes and algae toxins and their influencing factors in summer and autumn. Total nitrogen (TN), total phosphorous (TP), Fe, chlorophyla(Chla) and COD in water samples were determined. At the same time, water temperature (TEM), pH value, illumination, turbidity degree (TUR) of water body were recorded. In addition, the total number and attribute of algae cell and the content of microcystin-LR(MC-LR) and anatoxin-A(ANTX-A) were checked. The results showed that the pollution of both toxins was most serious in July. The MC-LR were mostly distributed in Wangxiang, but the ANTX-A were mostly distributed in Jishuigang. Generalized estimating equations (GEE) regression analysis showed that total number of algae cell was significantly correlated with TN, TP and Chla (P < 0.05). The distribution of MC-LR was significantly affected by total number of algae cells and TEM (P < 0.01), but TUR mainly affected the distributions of ANTX-A(P < 0.01). There was weak correlation between both toxins (P < 0.05). In short, there was a serious pollution of MC-LR, but ANTX-A pollution was light. The factors influencing the distributions of both algae toxins were not completely consistent.

Bacterial Toxins↗