Government and voluntary policymaking for sustainability in mining towns: A longitudinal analysis of Itabira,Brazil

The socio‐economic fabric of single‐company mining towns needs to be carefully considered by both Government and companies in sustainability policymaking. Policy design and effectiveness in such towns are significantly impacted by the city's economic dependence on a single company. This paper explores the perceived effectiveness of government and voluntary private sector mining policies for pursuing sustainability in the historic mining town of Itabira, Brazil over a period of 20 years. Itabira serves as a worthwhile case study because it allows for an in‐depth and longitudinal analysis that can reveal valuable lessons to policymakers of different sectors and jurisdictions located elsewhere. Based on extensive face‐to‐face interviews and literature reviews, study results indicate that changes to the state environmental licensing policies in the 1990s led to significant socio‐environmental improvements in the area. The globalization of the mining company also contributed to an increase in the quantity and quality of voluntary industry policies. Recent technological improvements in the beneficiation processes of the mining company promises to extend the life of the mine to 2050. Although there are significant incremental socio‐environmental policies and programmes, sustainability remains an elusive vision in Itabira, with no clear objectives or monitoring and accountability mechanisms. The paper concludes by recommending a more formal integrated policymaking framework.     

TMDL Balance: A Model for Coastal Water Pollutant Loadings

Bacterial contamination accounts for more than 60% of the impairments included on the 2008 Texas 303(d) List. Many of these bacterial impairments are along the Texas Gulf Coast because coastal waters often are regulated for oyster harvesting, which have strict water quality standards. Under the Clean Water Act, each one of these impaired waterbodies requires a total maximum daily load (TMDL) study to be performed. A recent, statewide study recommended the development and application of simple modeling approaches to address the majority of Texas's bacteria TMDLs, including “… simple load duration curve, GIS [geographic information systems], and/or mass balance models.” We developed the TMDL Balance model in response to this recommendation. TMDL Balance is a steady state, mass balance, GIS‐based model for simulating pollutant loads and concentrations in coastal systems. The model uses plug‐flow reactor and continuously‐stirred tank reactor equations to route spatially distributed point and nonpoint source loads through a watershed via overland flow, non‐tidal flow, and tidal flow, decaying the loads via first‐order kinetics. In this paper, we explain the development of the watershed loading portion of the TMDL Balance model, demonstrating the methodology through a case study: computing bacterial loads in the Copano Bay watershed of southeast Texas. The application highlights an example of distributing bacterial sources spatially based on land use data.     

Forest Edges as Nutrient and Pollutant Concentrators: Potential Synergisms between Fragmentation, Forest Canopies, and the Atmosphere

Abstract: Forest fragmentation leads to a dramatic increase in forest edge, and these edges may function as traps and concentrators for wind-borne nutrients and pollutants. We assessed the influence of forest edges on atmospheric deposition and subsequent inputs to the forest floor in deciduous-forest fragments in the eastern United States. To quantify these inputs, we collected throughfall—water that has passed through the forest canopy—from edge and interior zones of forests adjacent to open fields. During the 1995 growing season, atmospheric input (wet and dry deposition) of sulfur to forest edge zones was elevated compared with input to forest interiors. Throughfall fluxes of dissolved inorganic nitrogen and calcium were also greater at edges than interiors. The mean edge increases ranged from 17% to 56% for the nutrients and pollutants we measured. When we manipulated the structure of forest edges by removing all vegetation below half the canopy height, throughfall flux in the edge zone declined sharply and was less than that of the respective interior zone. Changing the vegetation structure of the edge also shifted the zone of highest throughfall flux farther into the interior of the forest. Our data suggest that forest edges can function both as significant traps for airborne nutrients and pollutants from adjoining agricultural or urban landscapes and effective concentrators of below-canopy chemical fluxes. These enhanced fluxes may have cascading effects on soil-nutrient cycling, microbial activity, seedling dominance, and other ecological processes near forest edges.     

Hematopoietic neoplasia inMya arenaria: Prevalence and indices of physiological condition

A field survey of hematopoietic neoplasia (Hn) in the soft shell clamMya arenaria (L.) was undertaken using an immunoperoxidase diagnostic technique. Monthly collections ofM. arenaria were made at two sites: Little Buttermilk Bay and New Bedford Harbor, both in Buzzards Bay, Massachusetts, USA, from May 1986 to October 1987. Clams were diagnosed for leukemia and analyzed for soft-tissue dry weight, condition index, and carbon and nitrogen content of the soft tissue. Prevalence of leukemia inM. arenaria exhibited a seasonal fluctuation with a maximum prevalence in fall (September to October) and a minimum prevalence in early summer (March to July). A second maximum peak in late winter (January to March) was observed at one site. Leukemia primarily affected clams that were 3 to 4 yr post-settlement. Lower prevalence levels were observed in both younger and older clams. LeukemicM. arenaria with advanced stages of the disease, were in poorer physiological condition based on dry weight of the soft tissue, condition index, and carbon content of the tissue. Nitrogen metabolism appeared to be unimpaired. Significant differences were observed between the two sites with respect to prevalence of Hn and the physiological condition of clams. Differences in disease prevalence between the two sites may be the result of unknown environmental factors that facilitate initiation of the disease or, that compromise the defense mechanisms of the clams.