Barriers to the adoption of proactive environmental strategies

This study contributes to the knowledge of the difficulties or barriers found by firms when adopting proactive environmental strategies, providing empirical evidence from 240 Spanish industrial firms. A set of 25 barriers are initially evaluated by the managers of the sample firms and are grouped into four types of difficulties facing firms: external barriers, endemic limitations of the firm, limited environmental motivation and limited preparation of employees and operational inertia. The estimation of a structural equation model leads us to conclude that only the barriers identified as endemic limitations of the firm can be characterized as “effective barriers”, defined as problems preventing firms from progressing toward proactive environmental behavior.     

Assays with Daphnia magna and Danio rerio as alert systems in aquatic toxicology

For the evaluation and monitoring of the water quality, a series of methodologies, which have as basis an ample variety of bioindicators, may be applied. The aim of this research was to evaluate the use of ecotoxicity assays with Daphnia magna and Danio rerio as alert systems in water contaminated with toxic substances. Using two toxicity databases, the sensibility of those aquatic organisms to a wide variety of chemical products and elements and to some chemical categories was investigated. The relation between the reference dose for human oral chronic exposure (RfD) of all chemical products and the acute toxicity values for both bioindicators was also studied. Acute toxicity tests with D. magna respond to a larger variety of chemicals with a higher sensitivity than those with D. rerio. Although mammals, crustaceans and fish have different routes of exposure, target organs and toxic mechanisms, acute toxicity essays with fish and Daphnia may be used as an initial screening before mammal models are used.     

Levels of PCDD/PCDFs and PCBs in edible marine species and human intake: a literature review

Polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs) are lipophilic organic compounds whose origin comes from many different sources. PCDD/Fs and PCBs are ubiquitous and persistent environmental pollutants with a well known potential toxicity, which were included at the 1998 UN-EC POP protocol. Although human exposure to PCDD/Fs and PCBs can occur by various routes, food is the primary source. A number of studies have shown that the major food sources of these organic pollutants are fat-containing animal products, including fish and other seafood. Because of the frequent health recommendations concerning fish consumption, to determine the contribution to the dietary intake of chemical contaminants such as PCDD/Fs and PCBs through fish and other seafood consumption is an issue of special interest. This paper reviews the state of the science regarding recent literature on PCDD/F and PCB levels in marine species and human intake through fish and seafood consumption. The concentrations of these pollutants depend basically on the environment in which the respective species are caught. It is concluded that some groups of population frequently consuming high quantities of certain species could be significantly increasing health risks due to PCDD/F and PCB exposure.     

Health implications of radon distribution in living rooms and bedrooms in U.K. dwellings--a case study in Northamptonshire

Environmental radon exposure of residents of domestic premises in the United Kingdom (UK) and elsewhere in Europe is estimated on the basis of the measured radon concentrations in, and the relative occupancies of, the principal living room and bedroom. While studies on radon concentration variability in the individual units in apartment blocks in various countries have been described, little data has been reported on variability in two-storey single-family dwellings, and the majority of extant studies consolidate living room and bedroom data early in the analysis. To investigate this further, detailed analysis was made of radon concentration data from a set of thirty-four homes situated in areas of Northamptonshire known to exhibit high radon levels. All homes were of typical UK construction of brick/block/stone walls under a pitched tile/slate roof. Approximately 50% of the sample were detached houses, the remainder being semi-detached (duplex) or terraced (row-house). Around 25% of the sample possessed cellars, while 12% were single-storey dwellings (bungalows), reflecting the typical incidence of this type of dwelling in England. In the two-storey homes, all monitored bedrooms were on the upper floor. Distribution of the ratios of bedroom/living room radon concentrations (BR/LR ratio) in individual properties was left-skewed (mean 0.67, median 0.73, range 0.05-1.05) with a tail extending to just above 1.0. The mean is consistent with the outcome of earlier extensive studies in England, while the variability depends principally on the characteristics of the property, and not on seasonal factors. In a small set of homes, the BR/LR ratio was anomalously low, (mean 0.3). BR/LR ratios in single-storey homes clustered around a value of 1.0, indicating that house design, rather than lifestyle, is the dominant factor in determining bedroom radon concentrations. Homes with higher mean annual radon concentrations showed lower BR/LR ratios, supporting our proposal that, in some homes, radon emanation from building materials may comprise a significant component of the overall radon level.     

Trends in the spatial and temporal distribution of 129I and 99Tc in coastal waters surrounding Ireland using Fucus vesiculosus as a bio-indicator

Spatial and temporal trends in (129)I and (99)Tc concentrations around the Irish coastline have been evaluated using Fucus vesiculosus as a bio-indicator. (129)I concentrations in a recent set of seawater samples have also been recorded and reveal an identical spatial pattern. Concentrations of (129)I in Fucus from the northeast coast of Ireland proved to be at least two orders of magnitude higher than concentrations in Fucus from the west coast. The (129)I content of Fucus increased significantly between 1985 and 2003, in line with increases in discharges of (129)I from the Sellafield nuclear reprocessing plant. Similar trends were observed in the case of (99)Tc. (129)I/(99)Tc ratios in Irish seawater were deduced from the Fucus data, and compared to ratios in discharges from Sellafield and from the French reprocessing plant at Cap de la Hague. Levels of (129)I and (99)Tc in Fucus from the west coast were found to be enhanced with respect to levels in seaweeds from other regions in the Northern Hemisphere unaffected by discharges from nuclear installations such as those referred to.     

Indoor radon monitoring in Northern Iran using passive and active measurements

In this work we present the results of a 2-year survey of indoor radon variations in four cities of Lahijan, Ardabil, Sar-Ein and Namin in North and Northwest Iran. We used both passive and active measurements by solid state nuclear track detectors (SSNTDs) with CR-39 polycarbonate and PRASSI Portable radon Gas Surveyor. A total of 1124 samplers in Lahijan, Ardabil, Sar-Ein and Namin were installed. Sampling frequency was seasonal and sampling locations were randomly chosen based on dwelling structures, floors, geological formations, elevation and temperature variation parameters. For quality assurance, 281 active measurements and double sampling were carried out. Based on our results and the results of previous surveys, Ardabil and Lahijan have the second and third highest radon concentration in Iran, respectively (Ramsar is first). The average radon concentration during the year in Lahijan, Ardabil, Sar-Ein and Namin were 163, 240, 160 and 144 Bq/m(3) with medians of 160, 168, 124 and 133 Bq/m(3), respectively. These concentrations give rise to annual effective doses of 3.43 mSv/y for Lahijan and 5.00 mSv/y for Ardabil. The maximum recorded concentration was 2386 Bq/m(3) during winter in Ardabil and the minimum concentration was 55 Bq/m(3) during spring in Lahijan. Relationships between radon concentration and building materials and room ventilation were also studied. The dosimetry calculations showed that these four cities could be categorized as average natural radiation zones. The correlation coefficients relating warm and cold season radon variation data were obtained.     

Optimisation of systems to locate discrete gamma-ray sources within a large search area

Most systems used to locate discrete gamma-ray sources involve systematically passing a detector over the search area while seeking a significant increase in the observed count-rate. This paper discusses the ways in which such systems may be designed to maximise the probability of locating a source. It is shown that optimised systems use a collimated, energy-discriminating detector and overlapping counting intervals determined by the scanning geometry and speed.     

Radiocesium in caribou and reindeer in northern Canada, Alaska and Greenland from 1958 to 2000

This study summarizes the spatial and temporal trends of fallout (137)Cs concentrations in caribou and reindeer (Rangifer tarandus ssp.), reported in various programs in Canada, Alaska and Greenland, over a 40-y period. During the 1960s, the highest (137)Cs concentrations (2000-3000Bqkg(-1) wet weight in muscle) were found in the large caribou herds of central northern Canada, with levels about 50% lower in Alaska and Greenland. Concentrations varied by up to a factor of 6 between spring and fall. Concentrations in reindeer were comparable to those in caribou from the same regions. The highest (137)Cs concentrations (750Bqkg(-1)) in the late 1980s were found in the Caniapiscau herd of central Québec. The contribution from the Chernobyl accident in 1986 was estimated from (134)Cs measurements to be 10-40% of the total (137)Cs. Present concentrations have declined to 200-300Bqkg(-1). The effective half-life (T(eff)) of (137)Cs in Canadian caribou herds was estimated to be about 6 y. The potential impact on the health of northern residents is discussed.     

Distribution of nuclear bomb Pu in Nishiyama area, Nagasaki, estimated by accurate and precise determination of 240Pu/239Pu ratio in soils

Plutonium isotopes in forest soils collected in Nishiyama area, Nagasaki, were successfully determined by high resolution inductively coupled plasma mass spectrometry after the treatment with a microwave decomposition system. The (240)Pu/(239)Pu atom ratios observed in the samples in the Nishiyama area were obviously lower than the range of the global fallout. The low ratios (minimum 0.032) observed in Nishiyama area indicated the influence of detonation of the Pu nuclear weapon in 1945. Since the area is contaminated also by global fallout, the (240)Pu/(239)Pu atom ratio can be more sensitive indicator of bomb-derived Pu than Pu activity concentration.     

Evaluation of the usefulness of bird feathers as a non-destructive biomonitoring tool for organic pollutants: a comparative and meta-analytical approach

In this study, we investigated whether bird feathers can be used as a non-destructive biomonitor for organic pollutants. We analysed the outermost tail feathers of 8 terrestrial and aquatic bird species from Belgium (8 species, n=108) for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs). Every compound class could be quantified in one single tail feather of the birds under study (sum PCBs ranging from 5.5 to 510 ng/g feather, sum PBDEs from 0.33 to 53 ng/g feather, sum DDTs from 1.5 to 730 ng/g feather), except for PBDEs in feathers of the common moorhen (Gallinula chloropus). Further, we calculated Pearson correlations between concentrations of organic pollutants in feathers and concentrations in corresponding muscle or liver tissue from the birds. Correlations were found significant in half of the cases of the terrestrial species, but were found not significant for the aquatic species, with the exception of a significant correlation of sum PCBs in the common moorhen. Only for the common buzzard (Buteo buteo) (n=43) all correlations were found significant (0.32相似文献