Industry-sponsored research on the potential health and environmental effects of selected brominated flame retardants

Modern fire-fighting techniques, equipment and fire-resistant building design has lead to less destruction than in the previous centuries. However, a high fuel load in either a residence or a commercial building can overwhelm even the best firefighters or building construction, and factors affecting the fuel load have changed in recent decades. The fire load in a typical home has doubled over the last 50 years, furnishings typically include those made of petrochemicals that can behave as if containing built-in accelerant, and modern energy-efficient buildings are less able to disperse heat in the event of a fire. Flame retardant chemicals (FRs) are one means used to reduce the risk of fire. FRs are typically added or incorporated chemically into a polymer to slow or hinder the ignition or growth of a fire in low-to-moderate cost commodity polymers. One type of FR contains bromine atoms as the active moiety. The FR industry, either as individual companies or as consortia, has conducted a broad range of studies on the commercial deca-, octa- and pentabromodiphenyl oxide/ether, tetrabromobisphenol A and hexabromocyclododecane products. These five products have data in excess of the OECD Screening Informational Data Set (SIDS) and the U.S. High Production Volume (HPV) program, and sufficient data for the performance of formal EU risk assessments. The objective of this paper is to present the range of data developed by industry consortia and to provide sources for the information. We hope to facilitate further research by assembling references to industry consortia-sponsored research here.     

Recovery of insular seabird populations years after rodent eradication

Seabirds have been particularly affected by invasive non-native species, which has led to the implementation of numerous eradication campaigns for the conservation of these keystone and highly vulnerable species. Although the benefits of eradication of invasive non-native species for seabird conservation have been demonstrated, the recovery kinetics of different seabird populations on islands after eradication remains poorly evaluated. We conducted long-term monitoring of the number of breeding pairs of seven seabird species on a small atoll, Surprise Island, New Caledonia (southwestern tropical Pacific). Marine avifauna of the island were surveyed yearly 4 years before to 4 years after rodent eradication (conducted in 2005), and we conducted multiple one-time surveys from ∼10 years before and ∼15 years after eradication. We sought to determine how different seabird species responded to the eradication of invasive rodents in an insular environment. Three species responded positively (two- to 10-fold increase in population size) to eradication with differences in lag time and sensitivity. The number of breeding pairs increased (effect sizes = 0.49–0.95 and 0.35–0.52) for two species over 4 years post-eradication due to immigration. One species had a longer (at least 5 years) response time than all others; breeding pairs increased for over 10 years after eradication. Long-term sampling was necessary to observe the responses of the seabird populations on the island because of the delayed response of a species to eradication not visible in the first years after eradication. Our results confirmed the positive effects of eradication of invasive non-native species on seabirds and emphasize the importance of mid- and long-term pre- and posteradication surveys to decipher the mechanisms of seabird recovery and confirm the benefits of eradication for conservation purposes.     

A comparison of the properties of the major commercial PBDPO/PBDE product to those of major PBB and PCB products

Decabromodiphenyl oxide (DBDPO), a highly effective polybrominated diphenyl oxide (PBDPO) flame retardant (FR) used primarily in electrical and electronic equipment, is the second highest volume brominated flame retardant (BFR) and accounts for 82% of the PBDPO usage globally. The apparent similarities in chemical structure between the DBDPO, polychlorinated and polybrominated biphenyl (PCB, PBB) molecules have led to the presumption that these substances also share similar toxicological and environmental properties. However, DBDPO's physical/chemical properties, applications, environmental release, and toxicology differ substantially from the former PCB/PBB products. DBDPO is a heavier and larger molecule than components of the predominant PCB/PBB products used in the past, and the commercial DBDPO product has a lower water solubility and vapor pressure than the former PCB and PBB products. DBDPO's detection in the environment is generally in sediments near known point sources, and its primary use in thermoplastics limits its environmental release from end products. PBB environmental release has been primarily associated with one accident occurring in the US in 1973. The PCBs, used in applications with a high potential for environmental release, were detected in diverse locations around the world as early as in the 1970s. Current releases of PCB are considered related to an environmental cycling process of congeners previously released into the environment; however, DBDPO's physical/chemical properties do not indicate a similar potential. Extensive testing of the DBDPO commercial product has demonstrated that it is toxicologically and pharmacokinetically different from the predominant PCB and PBB products used in the past. Thus, although the chemical structures of DBDPO, PBB, and PCB appear similar, the properties of DBDPO are distinctly different.     

A new method to study biodegradation kinetics of organic trace pollutants by activated sludge

A reliable prediction of the behaviour of organic trace compounds in activated sludge plants requires an accurate input of the biodegradation kinetics. Often these kinetics are extrapolated from the results of standardised biodegradation tests. However, these tests generally are not designed to yield kinetic information and do not reflect the conditions in activated sludge plants. To overcome these problems a new test method was developed which is referred to as a 'by-pass' test. The test methodology is explained and examples are given for three compounds: the C(12)-homologue of linear alkylbenzene sulfonate, nitrilotriacetic acid and toluene. More experience with the test is required, particularly with respect to selection of the proper test settings, which are compound related. The test is a suitable tool in a research environment, for example to investigate the effect of plant operational parameters on the biodegradation kinetics.     

ASSESSING ENVIRONMENTAL EFFECTS OF SEVERE SUSTAINED DROUGHT1

ABSTRACT: Evaluation criteria for reservoir and stream resources were developed to provide decision makers with feedback on environmental consequences of water allocation decisions under conditions of severe sustained drought within the Colorado River Basin by using the AZCOL gaming simulation model. Seven categories of flow dependent resources were identified which highlight resource states associated with reservoirs or river reaches within the AZCOL model. AZCOL directly simulates impact of water management decisions on five resource categories: threatened, endangered or sensitive fish; native nonlisted fish; wetland and riparian elements; national or state wildlife refuges; and hatcheries or other flow dependent facilities. Two additional categories - cold and warm water sport fish - are not modeled explicitly but are incorporated in the evaluation of monetary benefits from recreation on Colorado River waters. Each resource category was characterized at each time step in the simulation according to one of four environmental states: stable, threatened, endangered, or extirpated. Changes in resource states were modeled by time and flow-dependent decision criteria tied to either reservoir level or stream flows within the AZCOL model structure. Gaming results using the AZCOL model indicate environmental impacts would be substantial and that water allocation decisions directly impacted environmental resource states.     

Perceptions of climate change risks in primary resource use industries: a survey of the Canadian mining sector

A survey documenting how climate change is perceived, experienced, and responded to in the Canadian mining sector was administered to industry practitioners at the Prospectors & Developers Association of Canada annual meeting. Nine key findings from the survey are discussed: (1) The Canadian mining sector is sensitive to climate-related conditions. (2) Climate change is perceived to be having a negative impact on mining operations. (3) Companies are taking action to manage the current impacts. (4) Cost and uncertainty are commonly identified barriers to adapting to current climate change. (5) Future climate change is expected to have impacts for the industry. (6) Climate change projections are perceived as threats by the majority of respondents. (7) Despite the perceived threat, companies are not currently taking action to plan for future impacts. (8) Cost and uncertainty are commonly identified barriers to adapting to future climate change impacts. (9) The mining sector is currently making efforts to reduce greenhouse gas emissions. The survey is exploratory in nature, establishing a baseline for targeted research to assess in greater detail the vulnerability of mining to climate change.     

Does the canopy mixing layer model apply to highly flexible aquatic vegetation? Insights from numerical modelling

Vegetation is a characteristic feature of shallow aquatic flows such as rivers, lakes and coastal waters. Flow through and above aquatic vegetation canopies is commonly described using a canopy mixing layer analogy which provides a canonical framework for assessing key hydraulic characteristics such as velocity profiles, large-scale coherent turbulent structures and mixing and transport processes for solutes and sediments. This theory is well developed for the case of semi-rigid terrestrial vegetation and has more recently been applied to the case of aquatic vegetation. However, aquatic vegetation often displays key differences in morphology and biomechanics to terrestrial vegetation due to the different environment it inhabits. Here we investigate the effect of plant morphology and biomechanical properties on flow–vegetation interactions through the application of a coupled LES-biomechanical model. We present results from two simulations of aquatic vegetated flows: one assuming a semi-rigid canopy and the other a highly flexible canopy and provide a comparison of the associated flow regimes. Our results show that while both cases display canopy mixing layers, there are also clear differences in the shear layer characteristics and turbulent processes between the two, suggesting that the semi-rigid approximation may not provide a complete representation of flow–vegetation interactions.     

Modeling Production Efficiency and Greenhouse Gas Objectives as a Function of Forage Production of Dairy Farms Using Copula Models

Environmental Modeling & Assessment - Dairy farms are systems with multiple dependent variables whose practices influence their economic and environmental performances. Decisions made and...