A new multipollutant, no-threshold air quality health index based on short-term associations observed in daily time-series analyses

Air quality indices currently in use have been criticized because they do not capture additive effects of multiple pollutants, or reflect the apparent no-threshold concentration-response relationship between air pollution and health. We propose a new air quality health index (AQHI), constructed as the sum of excess mortality risk associated with individual pollutants from a time-series analysis of air pollution and mortality in Canadian cities, adjusted to a 0-10 scale, and calculated hourly on the basis of trailing 3-hr average pollutant concentrations. Extensive sensitivity analyses were conducted using alternative combinations of pollutants from single and multipollutant models. All formulations considered produced frequency distributions of the daily maximum AQHI that were right-skewed, with modal values of 3 or 4, and less than 10% of values at 7 or above on the 10-point scale. In the absence of a gold standard and given the uncertainty in how to best reflect the mix of pollutants, we recommend a formulation based on associations of nitrogen dioxide, ozone, and particulate matter of median aerodynamic diameter less than 2.5 microm with mortality from single-pollutant models. Further sensitivity analyses revealed good agreement of this formulation with others based on alternative sources of coefficients drawn from published studies of mortality and morbidity. These analyses provide evidence that the AQHI represents a valid approach to formulating an index with the objective of allowing people to judge the relative probability of experiencing adverse health effects from day to day. Together with health messages and a graphic display, the AQHI scale appears promising as an air quality risk communication tool.     

Intrauterine brain teratoma: a case report of imaging (US,MRI) with neuropathologic correlations

Fetal brain tumors are rare and teratoma is considered as the most common. Fetal MR Imaging is currently used to evaluate cases of ventricular dilatation. We report a case of cerebral immature teratoma detected by ultrasonography because of ventricular dilatation at 24 gestational weeks. MRI was the more accurate imaging method in depicting the tumor and its consequences on brain development as well as in taking a decision with regard to the management of pregnancy. Copyright © 2003 John Wiley & Sons, Ltd.     

Elements of a certification system for forestry-based carbon offset projects

Implementation of the Kyoto Protocol will require theestablishment of procedures for monitoring,verification and certification of carbon offsetprojects. In this paper, the steps required forindependent certification of forestry-based carbonoffset projects are reviewed, based on the proceduresused by the international certification companySociété Générale de Surveillance.Firstly, a project must be evaluated for itssuitability in relation to eligibility criteria of theKyoto Protocol. These eligibility criteria areclassified under four headings: (a) acceptability tohost country parties and international agreements; (b)additionality, in terms of demonstrated positivegreenhouse gas effects additional to the`business-as-usual' case; (c) externalities orunwanted side effects; and, (d) capacity to implementproject's activities. Secondly, the scientificmethodology for calculating the carbon offsets and themethodology for data collection and statisticalanalysis must be evaluated. Additionally, the amountof carbon offsets quantified must be adjusted toreflect the uncertainty associated with themethodology and data used. Only when these steps havebeen completed can carbon offsets be certified.Finally, the paper discusses the importance ofstandardization of methods and procedures used forproject monitoring and verification, and the need foraccreditation to ensure that the activities ofcertifiers are regulated.     

Characterization of i(18p) in prenatal diagnosis by fluorescence in situ hybridization

A case is presented in which chorionic villus direct preparation and cultured chorionic villus cells revealed a 47,XX, + mar karyotype. The marker was a small metacentric chromosome and appeared to be i(18p)—isochromosome 18p. Follow-up studies in both amniotic fluid and fetal fibroblasts confirmed the karyotype. In order to characterize the marker, a panel of biotinylated DNA probes was used, including a whole chromosome 18 probe, chromosome 18-specific alpha satellite DNA, Yac clones, and a pan-telomeric probe. These studies show that the marker is a monocentric i(18p) in which about 80 per cent of chromosome 18 alpha satellite DNA has been lost.     

Herbicides and nitrogen in precipitation: progression from west to east and contribution to the Marne river (France)

Herbicides and nitrogen fallout were studied in France at six sites from west to east. Atrazine, a herbicide widely used in France and forbidden in some European countries was found. Its fallout was quantified to 400 kg on the river Marne catchment (13 500 km2), an agricultural region located east of Paris. The average fallout contribution to the Marne river contamination was estimated at 20 ng/l from March to August. Independently of the wind direction, only a small part of this atmospheric contamination can reach adjacent countries.     

A decision support system for wet soil cleaning

Newly developed software can predict the essential characteristics of the sand product resulting from the ex-situ washing of contaminated soil, dredging sludge or breaker sand. The system was designed for the Dutch situation and it works on the basis of readily available information. The primary output of the system is an assessment of the reusability of the sand product, which is obtained by comparing the prediction of the residual contamination and engineering quality with accepted levels and standards for building materials. The system also provides a ranking of potential applications for the sand with respect to treatment cost, the amount of recycled material or the environmental quality of the product. The software integrates soil cleaning expertise and unit process modelling in a way that allows varying levels of refinement of input data, ranging from a simple identification of the pollution source to a detailed particle size distribution of the contaminated soil. Tests on a database containing information on 117 processed batches of soil, dredging sludge and breaker sand show an 80% success rate in predicting cleanability, even though the input contamination levels were predominantly taken from (relatively inaccurate) in-situ data.     

Metal Contamination of Sediments and Soils of Bayou Saint John: A Potential Health Impact to Local Fishermen?

This research examines the pattern of sediment contamination of an urban bayou of New Orleans (formerly a natural waterway) and the potential for human exposure from consumption of fish caught in the bayou. Sediments and soils of Bayou Saint John were evaluated for lead (Pb), zinc (Zn), and cadmium (Cd). Sediment cores were collected at bridges (n = 130) and sites between the bridges (n = 303) of the bayou. In addition, soil samples (n = 66) were collected along the banks of the bayou. Sediments below the bridges contain significantly more (p-value approximately 10(-7)) Pb and Zn (medians of 241 and 230 mg kg(-1), respectively) than bayou sediments located between bridges (medians of 64 and 77 mg kg(-1), respectively). Sediments below bridges of the upper reaches of the bayou contain significantly larger amounts of metals (p < 10(-14) for Pb and Zn and p approximately 10(-8) for Cd) (medians of 329, 383 and 1.5, respectively) than sediments below bridges in the lower reaches of the bayou (medians of 43, 31 and 0.5 for Pb, Zn and Cd, respectively). Likewise, medians for sediments located between bridges contain significantly (p < 10(-14)) higher quantities of Pb, Zn and Cd (170, 203 and 1.8 mg kg(-1), respectively) in the upper bayou than Pb, Zn, and Cd (48, 32, and 0.8 mg kg(-1), respectively) in the lower reaches of the bayou. The potential risk for human exposure may be magnified by the fact that fishing generally occurs from the numerous bridges that cross the bayou. Poor and minority people do most of the fishing. Most people (87%) indicated they ate fish they caught from the Bayou.     

In situ exposures using caged organisms: a multi-compartment approach to detect aquatic toxicity and bioaccumulation

An in situ toxicity and bioaccumulation assessment approach is described to assess stressor exposure and effects in surface waters (low and high flow), the sediment-water interface, surficial sediments and pore waters (including groundwater upwellings). This approach can be used for exposing species, representing major functional and taxonomic groups. Pimephales promelas, Daphnia magna, Ceriodaphnia dubia, Hyalella azteca, Hyalella sp., Chironomus tentans, Lumbriculus variegatus, Hydra attenuatta, Hexagenia sp. and Baetis tibialis were successfully used to measure effects on survival, growth, feeding, and/or uptake. Stressors identified included chemical toxicants, suspended solids, photo-induced toxicity, indigenous predators, and flow. Responses varied between laboratory and in situ exposures in many cases and were attributed to differing exposure dynamics and sample-processing artifacts. These in situ exposure approaches provide unique assessment information that is complementary to traditional laboratory-based toxicity and bioaccumulation testing and reduce the uncertainties of extrapolating from the laboratory to field responses.     

Diel variations in photoinduced oxidation of Hg0 in freshwater

Experiments have been conducted to determine diel variations in photoinduced Hg0 oxidation in lake water under natural Hg0(aq) concentrations. Pseudo-first-order rates of photooxidation (k') were calculated for water freshly collected in a Canadian Shield lake, Lake Croche (45 degrees 56' N, 74 degrees 00' W), at different periods of the day and subsequently incubated in the dark. Hg0 oxidation rates ranged from 0.02 to 0.07 h(-1), increasing from sunrise to noon and then decreasing throughout the remainder of the day. These changes paralleled those in sunlight intensity integrated over 1 h preceding water collection, and suggested that the water freshly collected in daylight was rich in photochemically produced Hg0 oxidants. It was also estimated that under intense solar radiation, even if oxidation rates reached a peak, reduction of Hg(II) was the prevalent redox process. Inversely, Hg0 oxidation overcame DGM production during the night or at periods of weaker light intensity. Overall, these findings explain the decreases in the DGM pool generally observed overnight. They also support previous reports that, during summer days, volatilization of Hg0 from water represent an important step in the Hg cycle in freshwater systems.