Markers of oxidative stress and toxicant exposure among young waterpipe smokers in the USA

Waterpipe (aka hookah) tobacco smokers are exposed to toxicants that can lead to oxidative DNA and RNA damage, a precursor to chronic disease formation. This study assessed toxicant exposure and biomarkers of DNA [8-oxo-7, 8-dihydro-2′-deoxyguanosine (8-oxodG)] and RNA [8-oxo-7,8-dihydroguanosine (8-oxoGuo)] oxidative damage during smoking of flavored and non-flavored waterpipe tobacco. Thirty waterpipe smokers completed two counterbalanced 2-h lab waterpipe smoking sessions (flavored vs. non-flavored waterpipe tobacco). Urinary concentrations of 8-oxodG and 8-oxoGuo and expired carbon monoxide (eCO) were measured before and after the smoking sessions. A significant increase in the urinary concentrations of 8-oxodG (from 2.12 ± 0.83 to 2.35 ± 0.91 ng/mg creatinine, p = 0.024) and 8-oxoGuo (from 2.96 ± 0.84 to 3.45 ± 0.76 ng/mg creatinine, p = 0.003) were observed after smoking the non-flavored and flavored waterpipe tobacco, respectively. Our results also showed that the mean ± SD of eCO increased significantly after smoking the flavored (from 1.3 ± 1.1 to 20.3 ± 23.6 ppm, p < 0.001) and non-flavored waterpipe tobacco (from 1.8 ± 1.2 to 24.5 ± 26.1 ppm, p < 0.001). There were no significant differences in the means of 8-oxodG (p = 0.576), 8-oxoGuo (p = 0.108), and eCO (p = 0.170) between the flavored and non-flavored tobacco sessions. Smoking non-flavored and flavored waterpipe tobacco leads to oxidative stress and toxicant exposure. Our findings add to the existing evidence about the adverse effects of waterpipe tobacco smoking (WTS) and the need for strong policies to inform and protect young people from the risks of WTS.

     

Effects of pen bedding and feeding high crude protein diets on manure composition and greenhouse gas emissions from a feedlot pen surface

Greenhouse gas (GHG) emissions from concentrated animal feeding operations vary by stage of production and management practices. The objective of this research was to study the effect of two dietary crude protein levels (12 and 16%) fed to beef steers in pens with or without corn stover bedding. Manure characteristics and GHG emissions were measured from feedlot pen surfaces. Sixteen equal-sized feedlot pens (19?×?23 m) were used. Eight were bedded approximately twice a week with corn stover and the remaining eight feedlot pens were not bedded. Angus steers (n = 138) were blocked by live weights (lighter and heavier) with 7 to 10 animals per pen. The trial was a 2?×?2 factorial design with factors of two protein levels and two bedding types (bedding vs. non bedding), with four replicates. The study was conducted from June through September and consisted of four ?28-day periods. Manure from each pen was scrapped once every 28 days and composite manure samples from each pen were collected. Air samples from pen surfaces were sampled in Tedlar bags using a Vac-U-Chamber coupled with a portable wind tunnel and analyzed with a greenhouse gas gas chromatograph within 24 hr of sampling. The manure samples were analyzed for crude protein (CP), total nitrogen (TN), ammonia (NH₃), total volatile fatty acid (TVFA), total carbon (TC), total phosphorus (TP), and potassium (K). The air samples were analyzed for methane (CH₄), carbon dioxide (CO₂), and nitrous oxide (N₂O) concentrations. The concentration of TN was significantly higher (p < 0.05) in manure from pens with cattle fed the high protein diets. The volatile fatty acids (VFAs) such as acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids concentrations were similar across both treatments. There were no significant differences in pen surface GHG emissions across manure management and dietary crude protein levels.

Implications: Livestock manure produces odor and emits GHGs (CO₂, CH₄, and N₂O) at different stages of production and management practices that have significant environmental concerns. Thus, it is important to measure GHG contributions from different sources and develop appropriate mitigation strategies for minimizing GHG contribution from livestock production facilities. Two dietary protein levels (12 and 16%) fed to beef steers in pens with or without corn stover bedding were studied. The results indicated that dietary protein levels and bedding vs. no bedding had very little effect on GHG emissions and manure composition under open feedlot conditions in North Dakota climatic conditions and management practices.     

Influence of GSTM1 and GSTT1 genotypes and confounding factors on the frequency of sister chromatid exchange and micronucleus among road construction workers

In the present study, we have investigated the influence of polymorphism of GSTM1 and GSTT1 genes and confounding factors such as age, sex, exposure duration and consumption habits on cytogenetic biomarkers. Frequency of sister chromatid exchanges (SCEs), high frequency cell (HFC) and cytokinesis blocked micronuclei (CBMN) were evaluated in peripheral blood lymphocytes of 115 occupationally exposed road construction workers and 105 unexposed individuals. The distribution of null and positive genotypes of glutathione-S transferase gene was evaluated by multiplex PCR among control and exposed subjects. An increased frequency of CBMN (7.03 ± 2.08); SCE (6.95 ± 1.76) and HFC (6.28 ± 1.69) were found in exposed subjects when compared to referent (CBMN - 3.35 ± 1.10; SCE - 4.13 ± 1.30 and HFC - 3.98 ± 1.56). These results were found statistically significant at p < 0.05. When the effect of confounding factors on the frequency of studied biomarkers was evaluated, a strong positive interaction was found. The individuals having GSTM1 and GSTT1 null genotypes had higher frequency of CBMN, SCE and HFC. The association between GSTM1 and GSTT1 genotypes and studied biomarkers was found statistically significant at p < 0.05. Our findings suggest that individuals having null type of GST are more susceptible to cytogenetic damage by occupational exposure regardless of confounding factors. There is a significant effect of polymorphism of these genes on cytogenetic biomarkers which are considered as early effects of genotoxic carcinogens.     

Assessment of heavy metals and their interrelationships with some physicochemical parameters in eco-efficient rivers of Himalayan region

Most precious and world famed Himalayan rivers like Ganga, Yamuna, and their tributaries are originated from Uttarakhand state of India. Over the years, increased industrial activities and urban growth along the rivers and lakes have resulted in increased load over the water bodies. In the present study, a comparison of characteristics of water quality with respect to heavy metals (Fe, Zn, Cu, and Pb) and their interrelationships with some physiological parameters during different seasons of year 2010 has been made in the water bodies flowing through the two geographical regions, namely Garhwal and Kumaon regions of the Himalayan State of India. All observed values of Pb, 02 observation of the Cu, and 59 observations of Fe are found exceed with the WHO standard for drinking water; 83 observations of Pb, 110 observations of Cu, and 59 observations of Fe are found exceed with the Bureau of Indian Standards. However, none of the observation of Zn is found exceeding with the standard limit. Cu shows the highest concentration 7.30 mg/l among all observations and also its higher concentration in Kumaon rivers. All the metals show negative correlation with dissolved oxygen and pH. Fe in river Yamuna system and Zn in Kumaon rivers show significant temporal variations at 90 % level of significance (LOS). However, no significant temporal difference of remaining metals is observed even at 95 % LOS. All metals except Fe in river Yamuna system show very significant variation in spatial distribution in different river systems at 95 % LOS.     

INTER-STATE WATER DISPUTES: A CASE STUDY OF INDIA1

ABSTRACT: During the last 27 years of independence, a large number of inter-state water disputes cropped up over the use of rivers. Surprisingly enough, more disputes developed in this short period than in the earlier 200 years of the development of irrigation and so far none of the disputes has been permanently solved. The major rivers of India are all inter-state rivers and this is one of the more important reasons why some of them are not yet fully developed for irrigation or power production. The Union Government has set up, so far, only three tribunals to adjudicate inter-state disputes. But the problems do not end simply by setting up the tribunals. In practice, it has also proved a dilatory process. None of the tribunals has been successful in settling any dispute in the long years of their existence. There is no codified law prescribing rights and the notion of “equity” has come to prevail restraining the upper states from drawing such quantities of water as would injure the interests of the lower states. Though the general principle of equitable apportionment had been advocated many times, in practice each contending state had given this principle an interpretation that suited it. The basic principle would be to harness the rivers not for the benefit of a particular state but for the maximization of agricultural, industrial, and navigational potential in the areas served by the rivers.     

Evaluation of Dust Generated from Basic Oxygen Furnace Steel Making

Abstract

A detailed characterization has been made of the dust generated during steel making in basic oxygen furnaces (BOF). Chemical composition and particle size distribution have been analyzed. X-ray diffraction, scanning electron microscopy, and electron probe micro-analysis techniques have been used to identify the morphology and the nature of the major iron-bearing phases as well as the gangue constituents. The dust characteristics have been found to be widely different, depending on the type of process used in BOF steel making, namely, suppressed combustion or total combustion. The type of dust abatement system (dry or wet) additionally influences the nature of the gangue constituents. The possibility of utilizing the iron-bearing major phases has been examined.     

The impact of coal utilization in Texas under the National energy plan

The paper describes the results of a study of the impact of the National Energy on the trend towards increased utilization of coal and lignite in Texas with forecasts of increased coal and lignite utilization for the electric utility and industrial sectors. Environmental impacts of this increased coal and lignite use are projected in terms of increased air pollutant emissions and air quality impacts. Economic costs of compliance with alternative source emission regulations are also projected for the electric utility industry.Lignite consumption in Texas under the National Energy Plan is projected to increase from the present 13 million metric tons in 1976 to 57 million metric tons annually by 1985. Sub-bituminous coal consumption in Texas is projected to increase from 1 million metric per year in 1976 to 49 million metric tons per year in 1985. Bituminous coal consumption in Texas is expected to increase from less than one million metric tons per year in 1976 to about 3 million metric tons per year in 1985.Major increases in sulfur oxides emissions from coal and lignite combustion in Texas can be expected by 1985 of up to 1.5 × 10⁹ kg per year without controls and 0.2 × 10⁹ kg per year with controls. Increases in acid precipitation formation will result in north-east Texas from extensive lignite usage for electric power generation as a detriment to agriculture. The photochemical air pollution problem in the Houston area will probably worsen primarily because of increased nitrogen oxides and sulfur oxides emissions because of industrial coal combustion. Capital costs of air pollution controls in Texas for coal-fired utility boilers are estimated as up to U.S. $3.9 billion by 1985, with total operating costs of up to U.S. $1.2 billion per year.     

Leisure/Labor Tradeoffs: The Backward-Bending Labor Supply in Fisheries

Economists have understood that the open-access nature of fishing grounds can cause the long-run fishery supply to bend backward. There is also increasing speculation that fishermen respond to falling output price either by increasing or decreasing effort, depending on the circumstances. This suggests a short-run backward-bending supply of fishing labor. A dynamic, utility-theoretic model of fishermen's behavior is developed to address this possibility. The model highlights both contemporaneous and intertemporal trade-offs between labor and leisure. The model is tested and the results indicate that the short-run labor supply in fisheries may exhibit backward-bending properties. In addition, changes in current prices may trigger changes in expectations of future prices, causing potentially greater counterintuitive behavior. These results challenge many traditional regulatory strategies (e.g., output taxes) that address problems of open access.     

Emissions from RDF/coal blended fuel combustion

The significant volume and weight reduction along with the energy potential of MSW, in the form of refuse derived fuel (RDF), has made its incineration an attractive alternative. However, the gaseous emissions such as, CO₂, CO, NO_x and SO₂, which are the byproduct of the combustion process pose serious environmental problems. These problems are compounded by the presence of certain highly regulated hazardous wastes such as, dioxins and furans in the exhaust stream. In the present investigation, different compositions of RDF/Coal blends were examined and the gaseous emissions from the combustion of the briquetted fuel were measured. Also, a direct comparison of emissions from RDF/coal blend incineration with coal combustion is presented in this paper. The potential for recovery of ferrous and non- ferrous metals provides an additional economic motivation for the use of RDF/Coal blended briquettes.     

Climate and Land Use Effects on Hydrologic Processes in a Primarily Rain‐Fed,Agricultural Watershed

Anticipating changes in hydrologic variables is essential for making socioeconomic water resource decisions. This study aims to assess the potential impact of land use and climate change on the hydrologic processes of a primarily rain‐fed, agriculturally based watershed in Missouri. A detailed evaluation was performed using the Soil and Water Assessment Tool for the near future (2020–2039) and mid‐century (2040–2059). Land use scenarios were mapped using the Conversion of Land Use and its Effects model. Ensemble results, based on 19 climate models, indicated a temperature increase of about 1.0°C in near future and 2.0°C in mid‐century. Combined climate and land use change scenarios showed distinct annual and seasonal hydrologic variations. Annual precipitation was projected to increase from 6% to 7%, which resulted in 14% more spring days with soil water content equal to or exceeding field capacity in mid‐century. However, summer precipitation was projected to decrease, a critical factor for crop growth. Higher temperatures led to increased potential evapotranspiration during the growing season. Combined with changes in precipitation patterns, this resulted in an increased need for irrigation by 38 mm representing a 10% increase in total irrigation water use. Analysis from multiple land use scenarios indicated converting agriculture to forest land can potentially mitigate the effects of climate change on streamflow, thus ensuring future water availability.