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PubMed1992

Zimbabwe's success story in education and health: will it weather economic structural adjustment?

The beginning of the 1980s saw the birth of Zimbabwe as a result of a protracted liberation war. It coincided with global interest in primary health care, the concept of universal primary school education and, unfortunately, moves towards economic stabilization and structural adjustment programmes. Economic structural adjustment was adopted by several sub Saharan African countries with dire consequences for the poor and vulnerable. Zimbabwe's commitment to social justice and to equitable distribution of resources demonstrated a practical move away from the culture of rhetoric so characteristic of many governments and non-governmental organisations and agencies. This commitment has been translated into impressive improvements in health and education. Current evidence shows that education has had a positive impact on health and related areas like contraceptive use, child mortality and the nutrition status of children. Conversely nutrition and health conditions among school children are important determinants of educational outcomes. Hitherto Zimbabwe's economy has been sufficiently strong to avoid excessive dependence on the International Monetary Fund, the World Bank and other foreign financial institutions. Unfortunately, however, the current economic recession together with economic structural adjustment programmes are beginning to have a negative impact on health and education. Will true synergism between health and education weather these structural problems? It seems that the people and government of Zimbabwe have the capacity and resolve to weather such a storm.

Economics↗
PubMed1998

Cytotoxicity of Kuwait weathered lake crude oil on rat hepatocytes: a histological and ultrastructural study.

In the present study, the cytotoxic effects of Kuwaiti weathered crude oil and a potent carcinogen (DMBA) on rat liver cells were examined by light and electron microscopy at each of 4 sampling periods after the start of low dosing (0.5 and 0.2 mg/kg) of feed. Such effects were compared with those of olive oil and uncontaminated food-exposed controls. The results confirm a pronounced cell damage which statistically not significant (p < 0.05). In crude oil, the organelle changes were variable and highly comparable to that of DMBA. The nuclei were mostly disintegrated while the cell showed demarcation of cytoplasmic vacuolization, lipid augmentation, and mitochondrial aberrations. The latter showed a remarkable association with the rough endoplasmic reticulum and lipid droplets, and appeared as decayed and diffused structures within the cell matrix. There was no comparable changes in the hepatocytes of animals fed with uncontaminated food except for the formation of lipid droplets in the olive oil-fed groups. Although the animals food was contaminated with Kuwaiti weathered oil formed in 1991 were exposed to extreme seasonal temperatures, yet the residues of such oil led to severe histopathological alterations in the liver cells which were similar to those of DMBA-treated cells. There is the need to pay attention to potential hazardous effects of the crude oil on environments.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed2004

Plant uptake and translocation of highly weathered, soil-bound technical chlordane residues: data from field and rhizotron studies.

It has been observed that plants are susceptible to uptake from soil and in planta transport of technical chlordane, in spite of its hydrophobicity and sequestration within the soil matrix due to weathering. Field and rhizotron studies were conducted with Cucurbitaceae planted in highly weathered, chlordane-contaminated soil to investigate details of soil-to-plant contaminant uptake. In the field-work, Cucurbita pepo L. (zucchini) was grown in soil at four levels of chlordane contamination: Clean (<limits of quantitation, 5 ng/g), low (average, 370 ng/g), medium (average, 1,951 ng/g), and high (average, 4,572 ng/g). The analysis of plant tissues (root, stem, leaf, and fruit) resulted in the detection of chlordane consistently at the highest concentration in the root tissue at each level of soil contamination. As the soil chlordane concentration increased, the average chlordane concentration in the root tissue increased as follows: Clean, 370 ng/g; low, 8,130 ng/g; medium, 21,800 ng/g; high, 29,400 ng/g. Further analysis of the field-grown plants showed distinct differences in both the proportional distribution of chlordane among the plant tissues and the pattern of the chlordane residues in each tissue type. These differences are attributed to plant uptake from soil versus uptake from air. In the rhizotron studies, uptake of chlordane residues by C. pepo L. was compared with that of another Cucurbitaceae, Cucumis sativus L. (cucumber). Xylem sap from the rhizotron-grown plants was collected and analyzed for chlordane, in addition to determination of chlordane residues in soil, roots, and aerial plant tissue. Component fractions and enantiomer fractions of both chiral and achiral chlordanes were followed through soil, root, xylem sap, and aerial tissue compartments. They indicate that the xenobiotic residues translocate enantioselectively from the soil matrix into and through the plant environment with genera-specific patterns. The determination of chlordanes at ng/g concentration explicitly for the first time in the xylem sap of plants grown in contaminated soil confirms the presence of a soil-sequestered and highly hydrophobic organic contaminant within the aqueous plant environment.

Air↗
PubMed2005

Influence of nutrient amendments on the phytoextraction of weathered 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene by cucurbits.

Field experiments were conducted to determine the impact of nutrient amendments on the phytoextraction of weathered 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (p,p '-DDE) by eight cultivars of cucurbits over a single growing season. Four cultivars of Cucurbita pepo ssp pepo are accumulators and extract percent level quantities of persistent organic pollutants (POPs), whereas C. pepo ssp ovifera and Cucumis sativus are nonaccumulators. The nonamended accumulators phytoextracted 1.0% of the p,p'-DDE and had a translocation factor of 0.44; however, the nonaccumulators removed 0.16% of the contaminant and had a translocation factor value of 0.09. The accumulators also had 3.8 times greater inorganic element content than the nonaccumulators. Duplicate mounds of each cultivar also received weekly nutrient amendments of phosphorus (400 mg/L K2HPO4), nitrogen (200 mg/L KNO3), or nitrogen/phosphorus (400 mg/L K2HPO4, 200 mg/L KNO3); a minus phosphorus treatment involved a 1-L addition of 1 g/L AlSO4 to the soil before planting. When normalized to respective control values (unamended vegetation), the root and stem p,p'-DDE bioconcentration factors (BCF) of the accumulator cultivars were significantly greater than those of the nonaccumulator cultivars under most nutrient regimes. The biomass of accumulator cultivars decreased by up to 61% under certain nutrient regimes, resulting in mixed effects on the amount of p,p'-DDE extracted. Treatment with N and P increased nonaccumulator biomass by 40 to 100%, and increased p,p'-DDE extraction from soil by 75%. Although generally assumed that fertilizer amendments will enhance phytoremediation, as evidenced here by the nonaccumulators, additions of macronutrients may reduce the phytoextraction of weathered POPs by C. pepo ssp pepo. These findings support our hypothesis that the ability of C. pepo ssp pepo to remove sequestered organic contaminants is governed by unique nutrient-acquisition mechanisms.

Alum Compounds↗
PubMed2001

Compositional and chiral profiles of weathered chlordane residues in soil.

The fate of chlordane and other persistent organic pollutants in the environment is of international concern. The behavior of persistent organic pollutants under both abiotic and biotic conditions must be determined for the comprehensive elucidation of their cycling through the biosphere. Standard analytical methods such as gas chromatography with electron capture detection are adequate for studies of cycling under abiotic conditions. Since two of the main components of technical chlordane, cis-chlordane and trans-chlordane, are optically active, chiral gas chromatography can be used to study the impact of biotic influences on chlordane's fate. We report here the use of chiral gas chromatography interfaced with ion trap mass spectrometry as part of an analytically rigorous method for the simultaneous determination of the compositional and chiral profiles of weathered soil residues of technical chlordane. Using the method described, several patterns in the long-term weathering of technical chlordane in soil are observed.

Chemical Phenomena↗
PubMed1984

A self-instructional manual for installing low-cost/no-cost weatherization materials: Experimental validation with scouts.

In this study, we describe the development and evaluation of a self-instructional program for installing 10 low-cost/no-cost weatherization materials (e.g., weatherstripping, caulking). This program was a weatherization and retrofit manual (WARM) providing step-by-step instructions and illustrations. Boy and Girl Scouts participated and used either the WARM or existing product instructions (EPI) to apply the materials. Scouts installed the materials properly only when they used the WARM.

Journal Article↗
PubMed2007

Vertical distribution and speciation of trace metals in weathering flotation residues of a zinc/lead sulfide mine.

Sulfide-bearing mine tailings are a serious environmental problem around the world. In this study, the vertical distribution and speciation of Zn and Pb in the fine-grained flotation residues of a former sulfide ore mine in Germany were investigated to assess the inorganic weathering processes that effect the environmental risk arising from this site. Total metal contents were determined by X-ray fluorescence spectroscopy (XRF). Mobilizable fractions of Zn, Pb, Fe, and Mn were quantified by sequential chemical extractions (SCE). Furthermore, the speciation of Zn was analyzed by Zn K-edge extended X-ray absorption fine structure spectroscopy (EXAFS) to identify the residual Zn species. The variations in pH and inorganic C content show an acidification of the topsoil to pH 5.5. EXAFS results confirm that Zn is mainly bound in sphalerite in the subsoil and weathering reactions lead to a redistribution of Zn in the topsoil. A loss of 35% Zn and S from the topsoil compared with the parent material with 10 g kg-1 Zn and neutral pH has been observed. If acidification proceeds it will lead to a significant release of Zn, S, and Pb to the ground water. In contrast to Zn, Pb is enriched in the mobile fraction of the topsoil by more than a factor of two compared with the subsoil which contains a total of 2 g kg-1 Pb. Thus, the high bioavailability of Pb and the potential for Pb uptake by plants and animals currently represent the most severe threat for environmental health.

Hydrogen-Ion Concentration↗
PubMed2006

Water quality criteria for total suspended solids (TSS) in urban wet-weather discharges.

Total suspended solids (TSS) from combined sewer overflows (CSOs) and stormwater discharges represent a crucial parameter for evaluating wet-weather pollution in urban areas. In fact, the increase of TSS in water during rain events can have ecotoxic effects on aquatic organisms. Furthermore, major potentially harmful substances such as heavy metals, PAHs and organic matter are adsorbed onto TSS and later settle on sediment. Water quality criteria for TSS consequently enable the risk of wet-weather pollution to be assessed, for instance to avoid detrimental effects on aquatic organisms. The criteria proposed in this study cover the short-term impact of TSS on fish (acute quality criteria AQC), taking into account the duration of their exposure in the receiving water. The concentration-exposure duration-effect curve proposed here thus predicts "ill effects" on fish for different exposure times and TSS concentrations. The ecotoxic effects of adsorbed pollutants are also taken into account with an additional safety factor. We implement this TSS criteria in a software that allows us to estimate the number of rain events that exceed a given morbidity threshold for fishes per year.

Cities↗
PubMedDate not supplied

Evaluation of high-rate clarification for wet-weather-only treatment facilities.

High-rate clarification (HRC) processes are well suited for enhanced primary treatment of wet-weather flows in combined sewer systems. Suspended solids removal in excess of 75% of influent concentrations can be achieved consistently. Chemical oxygen demand and five-day biochemical oxygen demand removal are better than 60%. However, although optimal treatment could be achieved in a matter of minutes when the units were started full, a delay of up to one-half hour was observed when the units were started empty. Operational strategies that minimize this effect need to be developed in full-scale tests before HRC processes can be implemented with confidence in wet-weather-only facilities.

Filtration↗
PubMed1987

Potassium carbonate as a potassium source and dietary buffer for lactating Holstein cows during hot weather.

Twenty-four lactating Holstein cows were offered diets containing .93, 1.29, and 1.53% potassium during hot weather. Cows fed 1.53% potassium consumed more dry matter than cows fed either .93 or 1.29% potassium. Milk production and composition were not different. Potassium intake and fractional excretion increased, and fecal output as a percentage of intake declined with diets containing 1.29 and 1.53% potassium. Magnesium fractional excretion was least and fecal output greatest in cows fed 1.29% potassium. Fecal sodium output and fecal output as a percentage of intake was reduced by 1.53% dietary potassium. During comparison period 2, potassium carbonate at 0, .5, or 1.0% had no effect on feed consumption or milk yield, but buffered diets increased milk fat percentage and depressed milk protein percentage. No effects of buffers on ruminal pH, volatile fatty acids, or digestibility of dry matter or fiber were noted. Cows responded favorably during hot weather to potassium supplementation at 1.53% of the diet, but with high dietary potassium, effects on other minerals must be considered. Chloride, although present above requirements in all diets, was greater in the highest potassium diet.

Animal Feed↗
PubMed1994

Wet brewers grains for lactating dairy cows during hot, humid weather.

Twenty lactating Jersey cows were offered diets containing 0, 15, or 30% wet brewers grains or 30% wet brewers grains plus liquid brewers' yeast during hot, humid weather. The DMI was not different, even though diets with 30% wet brewers grains contained only 35.5% DM and approximately 50 versus 36.8% NDF for the control diet. Yields of milk and FCM did not differ for cows offered the control diet versus wet brewers grains or diets with 15 versus 30% wet brewers grains, but milk yield for diets with 30% wet brewers grains was greater with added liquid brewers' yeast than without it. Milk fat percentage was not different, but milk protein percentage was lower, for diets with wet brewers grains than for controls and for 30% wet brewers grains than for 15% wet brewers grains. Serum urea N was lower for control cows than for cows receiving the diets with wet brewers grains. Feed cost per cow was lower for wet brewers grains versus the control diet, and income over feed cost was greater for diets with 30 versus 15% wet brewers grains. Large quantities of wet brewers grains can be added to the diet during hot weather without depressing DMI.

Animal Feed↗
PubMed1994

Diurnal fluctuations in plasma ions and water intake of dairy cows as affected by lactation in warm weather.

The presumption that water, Na, K, and Cl homeostasis is affected by the initiation of lactation, especially in hot weather, was examined. The study was conducted using five Israel Holstein cows at 1 to 2 wk before parturition (period 1) and at 2 wk (initiation of lactation) and 7 wk (established lactation) postpartum (periods 2 and 3, respectively). In period 1, most water intake was related to feed (in the absence of overt Na or osmotic stimuli). In contrast, during lactation, drinking was probably a combined response to feed-related and hypertonicity stimuli. Diurnal fluctuations in plasma ions, frequency of drinking, and volume ingested at each drinking increased postpartum. In period 2, plasma ion concentrations still were regulated around mean values, which was not the case in period 3, during which large diurnal variation in mean values occurred. The lowest values and highest variabilities were recorded in period 3 at midday. With the transition from the dry period to lactation, plasma concentrations of Na and Cl were reduced and became more labile, but the relationships between them remained stable. Plasma K seemed to vary independently of the two other ions. The reduced homeostatic efficiency of plasma ions during early and established lactation in hot weather may have consisted of an accumulation of their deficiencies, enhanced excretion of K in sweat, and sequestration of Na and Cl in the rumen.

Animals↗
PubMed2001

[A preliminary study on the organic carbon weathering fluxes in Beijiang River drainage].

Riverine water samples were collected from Hekou hydrometric station of Beijiang River in five hydrological seasons. The samples were analyzed of their organic carbon and total suspended substance, which demonstrated that the concentrations of particulate organic carbon (POC) changed synchronically with the concentrations of total suspended substance (TSS) in riverine water. The correlation between the concentrations of TSS and dissolved organic carbon (DOC), however, is sometimes positive and sometimes negative, and the correlation is not so notable as that between TSS and POC. With the concentration of total suspended substances increasing, the quality partition of organic carbon in total suspended substance decreased in a logarithm tendency. The transportation of organic carbon, especially of DOC, mainly takes place in flood peak periods. The weathering flux of organic carbon in Beijiang River drainage basin is about 10.01 x 10(6) g.km-2.a-1, which is constituted by 6.54 x 10(6) g.km-2.a-1 of POC and 3.47 x 10(6) g.km-2.a-1 of DOC. This pattern of organic carbon weathering flux in Beijiang drainage basin is consistent with that of most of the monsoon drainage basins.

Carbon↗
PubMedDate not supplied

Microbial growth and air pollution in carbonate rock weathering. Preliminary results of a in situ experimental study.

Preliminary results on limestone weathering caused by air pollution and microbial colonization are presented in this study. Outdoor exposure experimental assays were performed on Scaglia limestone samples. Samples were exposed in two areas in Perugia (Italy) that differ for degree of urban air pollution. At different times of exposure, ranging from 1 to 12 months, microbial contamination and textural modifications of sampled surfaces were evaluated by microbiological procedures, X-ray diffraction, and scanning electron microscopy. After one year of exposure a significant fungal colonization and the presence of weathering products (i.e. gypsum) were detected on sampled surfaces.

Air Pollutants↗
PubMed2002

Comparison of the pollutant loads in dry and wet weather runoff in a southern California urban watershed.

This research compares the relative contributions of potential contaminants discharged in dry weather flow (DWF) and wet weather flow (WWF) from the highly urbanized Ballona Creek watershed (BCW) in southern California using empirical and deterministic models. These models were used to compare the loading of the following pollutants: total suspended solids, biochemical oxygen demand, total nitrogen, total inorganic nitrogen, total Kjeldahl nitrogen, total phosphorus, copper, lead, arsenic, nickel, cadmium, and chromium. The results indicate DWF contributes approximately 10-30% of the total annual flow discharged from Ballona Creek. The annual DWF volume was fairly consistent; the variation in DWF percentage contribution was dependent on the highly variable volume of WWF. The relative contribution to the annual pollutant load varied considerably between each pollutant. In general, the DWF load was found to be significant, especially in years with lower precipitation totals. The results from this investigation have identified the relative relationship between DWF and WWF loads in the BCW and will aid in the decision-making process during the development of an integrated DWF-WWF management plan and allocation of water pollution control funds between DWF and WWF management.

California↗
PubMed1975

[Bronchial obstruction and bronchial hyperreactivity as a cause of difficulty in breathing that depends on burden and weather].

356 male patients (non-suffering from the lungs, recidivity-bronchitis or chronic bronchitis) were interrogated about the presence of difficulty in breathing that depends on burden and weather, and these patients were investigated for detection of a bronchial obstruction and a bronchial hyperreactivity. With the increased degree of a manifest bronchial obstruction a high-significant increase in frequency of load-dyspnea was demonstrated. On the other hand a significant increase of difficulty in breathing that depends on weather can be obtained only in patients with bronchial hyperreactivity. To estimate more differentiated the difficulty in breathing about which the patients pointed out, an investigation by means of the acetylcholine test is necessary.

Acetylcholine↗
PubMed2002

Project CARE: reducing wet weather overflows to improve beach water quality. Council Action in Respect of the Environment.

The people who live in North Shore City (New Zealand) consider the beaches as their greatest asset. Following public outcry on frequent beach pollution caused by wet weather sewer overflows, Project CARE commenced in 1998 to plan the improvements to the city's separated wastewater and stormwater systems to protect the streams and beaches, particularly from a public health perspective. The investigation included building hydrological and hydraulic models to represent the wastewater and stormwater systems and a receiving waters model to simulate the impacts on the beaches. These models were later used to explore options for improvement. It was found that North Shore City has a very leaky wastewater system that is under capacity. The resulting wet weather overflows (12 per year on average) are the most important contributor to the problem although stormwater pollution alone is big enough to cause problems (at a smaller magnitude). A cost optimisation model (iterative process using performance/cost relationships) was then used to assist in identifying the optimal set of improvement works (storage, repair and increased capacity, wastewater treatment plant) to meet different performance targets and to cater for growth up to the year 2050. Cost Benefit analyses, looking at improvements in system performance and water quality, show diminishing returns for performance levels better than 2 overflows per year. The total costs that meet this target are estimated at almost NZ$300M (US$135M).

Cost-Benefit Analysis↗
PubMed2002

Mechanical transmission of porcine reproductive and respiratory syndrome virus throughout a coordinated sequence of events during cold weather.

Using a field-based model, mechanical transmission of porcine reproductive and respiratory syndrome virus (PRRSV) wa assessed throughout a coordinated sequence of events that replicated common farm worker behavior during cold weather (< 0 degrees C). The model involved fomites (boots and containers), vehicle sanitation, transport, and the movement of personnel. A field strain of PRRSV was inoculated into carriers consisting of snow and water, and carriers were adhered to the undercarriage of a vehicle. The vehicle was driven approximately 50 km to a commercial truck washing facility where the driver's boots contacted the carriers during washing, introducing the virus to the vehicle interior. The vehicle was then driven 50 km to a simulated farm site, and the driver's boots mechanically spread virus into the farm anteroom. Types of containers frequently employed in swine farms (styrofoam semen cooler, metal toolbox, plastic lunch pail, and cardboard animal health product shipping parcel) contacted drippings from footwear on the anteroom floor. The truck wash floor, vehicle cab floor mats, boot soles, anteroom floor, and the ventral surface of containers were sampled to track the virus throughout the model. Ten replicates were conducted, along with sham-inoculated controls. At multiple sampling points PRRSV nucleic acid was detected in 8 of 10 replicates. In each of the 8 PCR-positive replicates, infectious PRRSV was detected on the surfaces of containers by virus isolation or swine bioassay. All sham-inoculated controls were negative. These results indicate that mechanical transmission of PRRSV can occur during coordinated sequence of events in cold weather.

Animal Husbandry↗