Changes in pesticide adsorption with time at high soil to solution ratios

Adsorption of six pesticides (2,4-D, dicamba, fluroxypyr, fluazifop-P, metsulfuron-methyl and flupyrsulfuron-methyl) in nine contrasting soils was measured using two techniques: (i) a classical batch method and (ii) a centrifugation method that allowed the measurement of adsorption at a realistic soil to solution ratio after one and seven days. Although the batch method gived significantly higher values of Kd than the centrifugation method for the more strongly sorbed molecules in the more sorptive soils, it tended to give lower adsorption coefficients compared to the centrifugation method when adsorption was lower. Discrepancies between the two methods were probably mainly due to the vigorous shaking applied in the batch technique that artificially enhances the availability of adsorption sites. This implies that shortly after application, more pesticide may be present in the soil solution and thus be available for degradation, plant uptake or leaching than will be predicted from adsorption coefficient determined using the batch method. Adsorption significantly increased between one and seven days and the extractability of total residues decreased with time. The increase in adsorption was not directly related to the level of adsorption although it was more important in soils containing more organic carbon (p=0.022). These results confirm the importance of time-dependent processes and the necessity to include them in risk assessment procedures. The centrifugation technique is a useful method to measure adsorption of pesticides at realistic soil moisture contents and seems to be an adequate technique to characterise the fraction of pesticide that is available for leaching at a given time after application.     

Community duplicate diet methodology: a new tool for estimating dietary exposures to pesticides

An observational field study was conducted to assess the feasibility of a community duplicate diet collection method; a dietary monitoring tool that is population-based. The purpose was to establish an alternative procedure to duplicate diet sampling that would be more efficient for a large, defined population, e.g., in the National Children's Study (NCS). Questionnaire data and food samples were collected in a residence so as not to lose the important component of storage, preparation, and handling in a contaminated microenvironment. The participants included nine Hispanic women of child bearing age living in Apopka, FL, USA. Foods highly consumed by Hispanic women were identified based on national food frequency questionnaires and prioritized by permethrin residue concentrations as measured for the Pesticide Data Program. Participants filled out questionnaires to determine if highly consumed foods were commonly eaten by them and to assess the collection protocol for the food samples. Measureable levels of permethrin were found in 54% of the samples. Questionnaire responses indicated that the collection of the community duplicate diet was feasible for a defined population.     

Comparison of averaging techniques for the calculation of the 'European average exposure indicator' for particulate matter

A comparison of various averaging techniques to calculate the Average Exposure Indicator (AEI) specified in European Directive 2008/50/EC for particulate matter in ambient air has been performed. This was done for data from seventeen sites around the UK for which PM(10) mass concentration data is available for the years 1998-2000 and 2008-2010 inclusive. The results have shown that use of the geometric mean produces significantly lower AEI values within the required three year averaging periods and slightly lower changes in the AEI value between the three year averaging periods than the use of the arithmetic mean. The use of weighted means in the calculation, using the data capture at each site as the weighting parameter, has also been tested and this is proposed as a useful way of taking account of the confidence of each data set.     

Particle count and black carbon measurements at schools in Las Vegas,NV and in the greater Salt Lake City,UT area

As part of two separate studies aimed to characterize ambient pollutant concentrations at schools in urban areas, we compare black carbon and particle count measurements at Adcock Elementary in Las Vegas, NV (April–June 2013), and Hunter High School in the West Valley City area of greater Salt Lake City, UT (February 2012). Both schools are in urban environments, but Adcock Elementary is next to the U.S. 95 freeway. Black carbon (BC) concentrations were 13% higher at Adcock compared to Hunter, while particle count concentrations were 60% higher. When wind speeds were low—less than 2 m/sec—both BC and particle count concentrations were significantly higher at Adcock, while concentrations at Hunter did not have as strong a variation with wind speed. When wind speeds were less than 2 m/sec, emissions from the adjacent freeway greatly affected concentrations at Adcock, regardless of wind direction. At both sites, BC and particle count concentrations peaked in the morning during commute hours. At Adcock, particle count also peaked during midday or early afternoon, when BC was low and conditions were conducive to new particle formation. While this midday peak occurred at Adcock on roughly 45% of the measured days, it occurred on only about 25% of the days at Hunter, since conditions for particle formation (higher solar radiation, lower wind speeds, lower relative humidity) were more conducive at Adcock. Thus, children attending these schools are likely to be exposed to pollution peaks during school drop-off in the morning, when BC and particle count concentrations peak, and often again during lunchtime recess when particle count peaks again.

Implications: Particle count concentrations at two schools were shown to typically be independent of BC or other pollutants. At a school in close proximity to a major freeway, particle count concentrations were high during the midday and when wind speeds were low, regardless of wind direction, showing a large area of effect from roadway emissions even when the school was not downwind of the roadway. At the second school, which sits in an urban neighborhood away from freeways, high particle counts occurred even though solar radiation was low during wintertime conditions, meaning that exposure to high particle counts can occur throughout the year.     

Efficacy of insurance for organisational disaster recovery: case study of the 2010 and 2011 Canterbury earthquakes

Insurance is widely acknowledged to be an important component of an organisation's disaster preparedness and resilience. Yet, little analysis exists of how well current commercial insurance policies and practices support organisational recovery in the wake of a major disaster. This exploratory qualitative research, supported by some quantitative survey data, evaluated the efficacy of commercial insurance following the sequence of earthquakes in Canterbury, New Zealand, in 2010 and 2011. The study found that, generally, the commercial insurance sector performed adequately, given the complexity of the events. However, there are a number of ways in which insurers could improve their operations to increase the efficacy of commercial insurance cover and to assist organisational recovery following a disaster. The most notable of these are: (i) better wording of policies; (ii) the availability of sector‐specific policies; (iii) the enhancement of claims assessment systems; and (iv) risk‐based policy pricing to incentivise risk reduction measures.     

PCB remediation in schools: a review

Growing awareness of polychlorinated biphenyls (PCBs) in legacy caulk and other construction materials of schools has created a need for information on best practices to control human exposures and comply with applicable regulations. A concise review of approaches and techniques for management of building-related PCBs is the focus of this paper. Engineering and administrative controls that block pathways of PCB transport, dilute concentrations of PCBs in indoor air or other exposure media, or establish uses of building space that mitigate exposure can be effective initial responses to identification of PCBs in a building. Mitigation measures also provide time for school officials to plan a longer-term remediation strategy and to secure the necessary resources. These longer-term strategies typically involve removal of caulk or other primary sources of PCBs as well as nearby masonry or other materials contaminated with PCBs by the primary sources. The costs of managing PCB-containing building materials from assessment through ultimate disposal can be substantial. Optimizing the efficacy and cost-effectiveness of remediation programs requires aligning a thorough understanding of sources and exposure pathways with the most appropriate mitigation and abatement methods.     

Climate Change and Forest Communities: Prospects for Building Institutional Adaptive Capacity in the Congo Basin Forests

Tropical forests are vulnerable to climate-change representing a risk for indigenous peoples and forest-dependent communities. Mechanisms to conserve the forest, such as REDD+, could assist in the mitigation of climate change, reduce vulnerability, and enable people to adapt. Ninety-eight interviews were conducted in three countries containing the Congo Basin forest, Cameroon, CAR, and DRC, to investigate perceptions of decision-makers within, and responses of the institutions of the state, private sector, and civil society to the challenges of climate change. Results indicate that while decision-makers’ awareness of climate change is high, direct institutional action is at an early stage. Adaptive capacity is currently low, but it could be enhanced with further development of institutional linkages and increased coordination of multilevel responses across all institutions and with local people. It is important to build networks with forest-dependent stakeholders at the local level, who can contribute knowledge that will build overall institutional adaptive capacity.     

Membrane bioreactor treatment of commonly used organophosphate pesticides

Five pesticide formulations registered for use in Canada containing organophosphate-insecticide active ingredients azinphos-methyl, chlorpyrifos, diazinon, malathion and phorate were subjected to treatment by membrane bioreactor (MBR) technology. The target active ingredients were introduced to the MBR at ppm level concentrations. The biodegradation of these compounds was analyzed daily using selected ion monitoring gas chromatography-mass spectrometry (GC/MS-SIM) following extraction of the analytes using solid-phase extraction (SPE). Amounts measuring 83 % to 98 % of the target analytes were removed with steady-state concentrations being reached within 5 days of their introduction. The dissolved oxygen, temperature, pH, and total heterotrophic bacterial population were monitored daily to ensure optimal conditions for biodegradation. The quality of the effluent from the MBR was assessed daily through spectrophotometric methods. Measurements were conducted for the concentration of ammonia, nitrate, nitrite, total and reactive phosphorus, as well as the chemical oxygen demand (COD) of the effluent. This study demonstrated that the MBR technology is feasible and efficient for treatment of organophosphate pesticides without introducing additional chemical additives.     

Midas’ Not-So-Golden Touch: On the Demise of Methyl Iodide as a Soil Fumigant in California

The demise of the soil fumigant, Midas, was heralded as a major environmental movement achievement, when Arysta LifeScience eventually deemed it economically non-viable and withdrew from US markets just before resolution of a lawsuit. Building on scholarship that focuses on strategy to understand how social movements sometimes win, we show how activist tactics were able to exploit the missteps of their opponents. These included the unreasonable expectations of Arysta for grower adoptions, the foibles of the director of California's Department of Pesticide Regulation in registering the chemical, and the reluctance of California's strawberry industry to discontinue use of methyl bromide. Although activist tactics, such as public comments and protests, had only a modest impact on the regulatory process, they had a major impact on grower adoptions of the chemical. This, together with a lawsuit that was not going well for the defendants, ultimately led to the withdrawal. Still, there was a great deal of luck involved, especially in the lawsuit in which the judge made rulings and statements favourable to the plaintiffs. Here, ‘scientization’, worked in favour of the movement rather than the industry.