Temporal variability of atmospheric particulate matter and chemical composition during a growing season at an agricultural site in northeastern China

This study presents the observations of PM_(10) and PM_(2.5) concentrations at an agricultural site from April to October 2012 in Dehui city,China.Ambient air was sampled by filter-based samplers and online PM monitors.The filter samples were analyzed to determine the abundance of ionic/inorganic elements,organic carbon(OC) and elemental carbon(EC).The daily PM_(10) concentrations varied significantly over the monitoring period,with an average of168 ± 63(in the range of 52-277) μg/m~3 during the land preparation/planting period(26 April-15 June),85 ± 65(36-228) μg/m~3 during the growing season(16 June-25 September),and 207 ±88(103-310) μg/m~3 during the harvest period(26 September-31 October).PM_(2.5) accounted for44%,56%and 66%of atmospheric PM_(10) during these periods,respectively.The PM_(10) diurnal variation showed a distinct peak from 16:00 to 21:00(LST) during the growing and harvesting seasons,while a gradual increase throughout the daytime until 17:00 was observed during tilling season.Mineral dust elements(Al,Ca,Fe,and Mg) dominated the PM_(10) chemical composition during the tilling season;OC,NO_3~-,SO_4~(2-) and NH_4~+ during the growing season;and carbonaceous species(i.e.,OC and EC) during the harvesting season.Our results indicate that the soil particles emitted by farm tillage and organic matter released from straw burning are the two most significant sources of PM_(10) emissions contributing to the recurring high pollution events in this region.Therefore,development of agricultural PM inventories from soil tillage and straw burning is prioritized to support air quality modeling.     

Cadmium in soybeans and the relevance to human exposure

<正>Introduction Cadmium is considered a human carcinogen by the International Agency for Research on Cancer(IARC,1993)and the US National Toxicology Program(NTP,1997).Cadmium contamination of food crops is a persistent issue for both the agricultural industry as well as consumers.This is an issue for agriculture because cadmium can be present in soils naturally or as a result of industrial processes and can contaminate foods that are consumed by humans.Industrial     

Implementing the Water Framework Directive: Contract Design and the Cost of Measures to Reduce Nitrogen Pollution from Agriculture

The performance of different policy design strategies is a key issue in evaluating programmes for water quality improvement under the Water Framework Directive (60/2000). This issue is emphasised by information asymmetries between regulator and agents. Using an economic model under asymmetric information, the aim of this paper is to compare the cost-effectiveness of selected methods of designing payments to farmers in order to reduce nitrogen pollution in agriculture. A principal-agent model is used, based on profit functions generated through farm-level linear programming. This allows a comparison of flat rate payments and a menu of contracts developed through mechanism design. The model is tested in an area of Emilia Romagna (Italy) in two policy contexts: Agenda 2000 and the 2003 Common Agricultural Policy (CAP) reform. The results show that different policy design options lead to differences in policy costs as great as 200–400%, with clear advantages for the menu of contracts. However, different policy scenarios may strongly affect such differences. Hence, the paper calls for greater attention to the interplay between CAP scenarios and water quality measures.     

Shorter fries? An alternative policy to support a reduction of nitrogen contamination from agricultural crop production

Feeding the growing population of the world poses significant policy challenges for the sustainability of global ecosystems. A prime example is the degradation of water quality due to the growing imbalance in the terrestrial nitrogen (N) cycle linked to increasing production of reactive N (Nr). Environmental impacts such as groundwater quality degradation and eutrophication of coastal estuaries tend to be local in nature but may be closely connected to global economic factors. Environmental accounting of the N fluxes entering, leaving or remaining in Prince Edward Island (PEI), a small agricultural region, demonstrate the importance of a single industry (potato production) in controlling the local N cycle. The resulting burden of Nr has its most profound effect on groundwater, the sole source of drinking water and the primary pathway of N to the Province's economically and ecologically important estuaries. At the same time, agriculture is a vital part of the local economy, and regulators are faced with the challenge of meeting environmental goals and still maintaining an industry that is competitive and responsive to global market trends. New, innovative policy alternatives are needed to foster more effective implementation of sustainable agricultural practices. An approach that focuses on influencing consumer choices toward more environmentally responsible production practices at the point of origin may help remove some of the important, non-technical barriers to sustainable food production practices. In practice, a system that documents the environmental performance throughout the full supply chain from producer to retailer would have to be implemented.     

Changes in the cell size of the diatom Cylindrotheca closterium in a hyperhaline pond

Cell length of the diatom Cylindrotheca closterium (Ehr.) Reimann & Lewin was investigated on a fortnightly basis from January to April 2000 in a hyperhaline pond (Sardinia, Mediterranean Sea) and relationships, with changes in temperature, salinity, and nitrite concentrations were assessed using single and multiple regression analyses. Results of our study indicate that C. closterium cell size was inversely related to temperature changes, but that salinity and nitrite concentrations may have a major idiosyncratic effect on cell size variability.     

Agricultural area impacts within a natural area: Cades cove,a case history

Agricultural management in Cades Cove, an historic district in Great Smoky Mountains National Park, has affected natural resources both within the district and in the adjoining natural areas. Aquatic impacts of haying and cattle grazing included increases in water temperatures, turbidity, nutrient loading, and bacterial counts and decreases in benthic macroinvertebrate density and fish biomass. Wildlife populations, including groundhogs, wild turkeys, and white-tailed deer, have increased in the open fields and around the periphery of the historic district. Intensive deer foraging has removed deciduous seedlings and saplings from woodlots, lowering species diversity and favoring coniferous reproduction. Cades Cove has limestone habitats unique in the park, and both deer browse and cattle grazing may have disturbed populations of rare plant species. Effects on water quality are detectable at a campground 15 stream km from the agricultural area, and the effects of deer foraging extend about 1 km beyond the open fields.Since historic landscape preservation is presently a goal of the park, managing for open vistas in Cades Cove will require some sort of continuing disturbance. Conversion of cattle pastures to hayfields would reduce aquatic impacts but the deer herd might increase as a result of reduced competition for forage. Retarding old field succession would increase populations of native plant species dependent on sunlight, but would require government-funded mowing. Other options are discussed. Completely eliminating the effects of the historic district on adjoining areas may be impossible, at least under present economic constraints.     

Sydney tar ponds: some problems in quantifying toxic waste

Information on the type and amount of hazardous and toxic waste is required to develop a meaningful strategy and estimate a realistic cost for clean up of the Sydney Tar Pond site which is located on Cape Breton, in the province of Nova Scotia, Canada. The site covers the area of the decommissioned Sysco (Sydney Steel Corporation) plant. The materials of concern include BTEX (benzene, toluene, ethylbenzene, and xylenes), PAH (polycyclic aromatic hydrocarbons), PCB (polychlorinated biphenyl), and particulates laden with toxic metals, such as arsenic, lead, and others. The originally nontoxic materials such as soil, blast furnace slag, and vegetation, as well as surface and ground waters, which were subsequently contaminated, must also be included if they fail tests prescribed by environmental regulations. An extensive sampling program must be undertaken to obtain data for an accurate estimate of the waste to be cleaned and disposed of. Apparently, 700,000 tons of toxic waste, which is believed to be present on the site, may represent only a fraction of the actual amount. The clean-up of the site is only part of the solution. Toxic waste has to be disposed of in accordance with environmental regulations.     

WATER CHEMISTRY OF NORTHERN GREAT PLAINS STRIP MINE AND LIVESTOCK WATER IMPOUNDMENTS1

The water from 34 strip mine and 9 livestock water impoundments on the Northern Great Plains was analyzed. In all areas the water was classified as slightly brackish or saline. The dominant ion sequence for the study ponds was Na>Ca>Mg>K and SO₄HCO₃CO₃Cl, which differs from most freshwater by the transposition of Na and SO₄. Even though mean concentrations of total filterable residue were consistently greater in strip mine ponds, statistically significant differences were not found at the p ≤ 0.05 level between strip ponds and livestock ponds. The macronutrients of nitrogen and phosphorus found in the ponds were neither limiting to primary productivity nor excessive for fresh water. Many ponds contain turbid water. Turbidity restricts light penetration and limits photosynthesis besides making the ponds visually unattractive. The source of water for the pond, whether surface runoff or groundwater, seems to have important bearing on turbidity. The most appropriate use of these strip mine ponds is for waterfowl, warm-water fisheries, and other wildlife associated with prairie wetlands. However, even these uses are jeopardized by detrimental concentrations of trace elements in the water (Anderson and Hawkes, 1984).     

Disaster Management for Nandira Watershed District Angul (Orissa) India, Using Temporal Remote Sensing Data and Gis

NALCO – the largest exporter of aluminium in India has a power plant of 720 MW capacity in Nandira watershed in Angul district of Orissa. The power plant utilises local coal to generate thermal power and disposes of large amount of ash which accumulates in slurry form at nearby two ash ponds. These ash ponds were breached on 31 December 2000, causing ash accumulation for entire regime of the Nandira river. An attempt has been made towards preparation of recovery and rehabilitation plan for NALCO using temporal Remote Sensing data and GIS. Indian remote sensing satellite data for pre-breach condition 12 December 2000, during breach event 31 December 2000 and post-breach condition 4 and 6 January 2001 has been digitally analysed for Nandira watershed. The satellite data of coarse spatial resolution provides the absence and presence of fresh sediment deposition along Nandira watershed and Brahmani river pertaining to pre-breach and post-breach conditions respectively on regional scales. The temporal comparison of fine resolution has clearly highlighted the aerial extent of damage caused by the disaster for entire watershed on local scales. The GIS has helped in demarcation of freshly accumulated ash at interval of 500 m along the river length as well as in delineation of maximum ash accumulation across the river width. The study has clearly demonstrated the use of temporal Remote Sensing data in conjunction with GIS for disaster management in terms of recovery and rehabilitation plan preparation of the Nandira watershed.     

FECAL COLIFORM SOURCE ASSESSMENT IN A SMALL,MIXED LAND USE WATERSHED1

ABSTRACT: This study presents the results of fecal coliform (FC) sampling in the Rawls Creek, South Carolina, watershed during 1999 and 2000. The work was undertaken because the watershed is listed on the 303(d) list for South Carolina due to FC excursions. The watershed is 43.8 percent residential, 35 percent forest, 5.7 percent mixed urban, 4.9 percent commercial, and 4.8 percent agriculture. Samples were taken at 15 stations during eight field trips divided into two phases to characterize FC inputs from subbasins and to integrate results from upstream sampling. FC concentrations ranged from 135 to 730 colonies/100 ml. Results suggest that retention ponds in the area are a significant factor in attenuation of FC concentrations. Catchments with the largest contiguous impervious areas are the greatest source of FC. The highest concentrations of FC were observed at stations just downstream from a large detention basin that intercepts storm runoff from a large commercial area. Further analysis of the design and performance of that structure is suggested. The Koon Branch tributary is less than 20 percent of the land area in the watershed but may contribute 40 percent of the fecal loading. The results of this study confirm the importance of site assessments to aid understanding of nonpoint source pollution in complex watersheds.