Community air monitoring for pesticides. Part 1: selecting pesticides and a community

The CA Department of Pesticide Regulation (CDPR) developed methods to select pesticides and a community to fulfill criteria for an ambient air monitoring study it conducted as part of the CA Environmental Protection Agency's Environmental Justice Action Plan. Using a scoring system, CDPR evaluated 100 pesticides based on statewide-reported pesticide use, volatility, and priority in CDPR's risk assessment process (indicators of exposure and toxicity) to produce a list of pesticides to consider as candidates for monitoring. The CDPR also evaluated and scored 83 communities based on demographics and health factors, availability of cumulative impacts data, and reported pesticide use to create a list of community candidates. The scores provide relative rankings to distinguish more highly impacted communities from less impacted ones and to identify which pesticides might contribute most to potential adverse health effects. These methods use criteria that can be quantified, validated, and verified in order to provide a transparent and fair selection process. Based on public comments and highest scores, CDPR recommended 40 pesticides (including some of their degradation products) and one community for its yearlong monitoring study. The CDPR then further refined its list of pesticides by soliciting input from local and technical advisory groups. The CDPR plans to use these methods to select pesticides and communities in future monitoring activities.     

How Do River Nitrate Concentrations Respond to Changes in Land-use? A Modelling Case Study of Headwaters in the River Derwent Catchment,North Yorkshire,UK

A combined semi-distributed hydrological model (CASCADE/QUESTOR) is used to evaluate the steady-state that may be achieved after changes in land-use or management and to explore what additional factors need to be considered in representing catchment processes. Two rural headwater catchments of the River Derwent (North Yorkshire, UK) were studied where significant change in land-use occurred in the 1990s and the early 2000s. Much larger increases in mean nitrate concentration (55%) were observed in the catchment with significant groundwater influence (Pickering Beck) compared with the surface water-dominated catchment (13% increase). The increases in Pickering Beck were considerably greater than could be explained by the model in terms of land-use change. Consequently, the study serves to focus attention on the long-term increases in nitrate concentration reported in major UK aquifers and the ongoing and chronic impact this trend is likely to be having on surface water concentrations. For river environments, where groundwater is a source, such trends will mask the impact of measures proposed to reduce the risk of nitrate leaching from agricultural land. Model estimates of within-channel losses account for 15–40% of nitrate entering rivers.     

Socio-environmental consideration of phosphorus flows in the urban sanitation chain of contrasting cities

Understanding how cities can transform organic waste into a valuable resource is critical to urban sustainability. The capture and recycling of phosphorus (P), and other essential nutrients, from human excreta is particularly important as an alternative organic fertilizer source for agriculture. However, the complex set of socio-environmental factors influencing urban human excreta management is not yet sufficiently integrated into sustainable P research. Here, we synthesize information about the pathways P can take through urban sanitation systems along with barriers and facilitators to P recycling across cities. We examine five case study cities by using a sanitation chains approach: Accra, Ghana; Buenos Aires, Argentina; Beijing, China; Baltimore, USA; and London, England. Our cross-city comparison shows that London and Baltimore recycle a larger percentage of P from human excreta back to agricultural lands than other cities, and that there is a large diversity in socio-environmental factors that affect the patterns of recycling observed across cities. Our research highlights conditions that may be “necessary but not sufficient” for P recycling, including access to capital resources. Path dependencies of large sanitation infrastructure investments in the Global North contrast with rapidly urbanizing cities in the Global South, which present opportunities for alternative sanitation development pathways. Understanding such city-specific social and environmental barriers to P recycling options could help address multiple interacting societal objectives related to sanitation and provide options for satisfying global agricultural nutrient demand.

     

Free market ideology and deregulation in Colorado’s oil fields: Evidence for triple movement activism?

Unconventional oil and gas extraction (UOGE) has spurred an unprecedented boom in onshore production in the US. Despite a surge in related research, a void exists regarding inquiries into policy outcomes and perceptions. To address this, support for federal regulatory exemptions for UOGE is examined using survey data collected in 2015 from two Northern Colorado communities. Current regulatory exemptions for UOGE can be understood as components of broader societal processes of neoliberalization. Free market ideology increases public support for federal regulatory exemptions for UOGE. Perceived negative impacts do not necessarily drive people to support increased federal regulation. Utilizing neo-Polanyian theory, interaction between free market ideology and perceived negative impacts is explored. Free market ideology appears to moderate people’s views of regulation: increasing the effect of perceived negative impacts while simultaneously increasing support for deregulation. To conclude, the ways in which free market ideology might normalize the impacts of UOGE activity are discussed.     

Another avenue of action: an examination of climate change countermovement industries’ use of PAC donations and their relationship to Congressional voting over time

The political mobilization of American business elites in the 1970s and 1980s has been well studied by political scientists. Environmental sociologists have explored how industries in this elite countermovement have organized to prevent environmental legislation. The literature often focuses on the efforts of this movement to shape public opinion on climate change. However, political scientists argue business elites are running several parallel strategies simultaneously in order to protect their interests. FEC data are utilized in multilevel logit models to examine how donations from industrial Political Action Committees (PACs) relate to Congressional representative’s environmental voting behavior over a 20-year period. Industries associated with the environmental countermovement have increasingly used PAC donations over time, and every additional $10,000 a representative received from countermovement industries significantly decreased odds of their taking the pro-environmental stance even when controlling for representatives’ demographics, districts, Congressional polarization and time-period.     

Toward a robust analytical method for separating trace levels of nano-materials in natural waters: cloud point extraction of nano-copper(II) oxide

Cloud point extraction (CPE) factors, namely Triton X-114 (TX-114) concentration, pH, ionic strength, incubation time, and temperature, were optimized for the separation of nano-sized copper(II) oxide (nCuO) in aqueous matrices. The kinetics of phase transfer was studied using UV–visible spectroscopy. From the highest separation rate, the most favorable conditions were observed with 0.2 %?w/v of TX-114, pH?=?9.0, ionic strength of 10 mM NaCl, and incubation at 40 °C for 60 min, yielding an extraction efficiency of 89.2?±?3.9 % and a preconcentration factor of 86. The aggregate size distribution confirmed the formation of very large nCuO–micelle assemblies (11.9 μm) under these conditions. The surface charge of nCuO was also diminished effectively. An extraction efficiency of 91 % was achieved with a mixture of TX-100 and TX-114 containing 30 wt.% of TX-100. Natural organic and particulate matters, represented by humic acid (30 mg/L) and micron-sized silica particles (50 mg/L), respectively, did not significantly reduce the CPE efficiency (<10 %). The recovery of copper(II) ions (20 mg/L) in the presence of humic acid was low (3–10 %). The spiked natural water samples were analyzed either directly or after CPE by inductively coupled plasma mass spectrometry following acid digestion/microwave irradiation. The results indicated the influence of matrix effects and their reduction by CPE. A delay between spiking nCuO and CPE may also influence the recovery of nCuO due to aggregation and dissolution. A detection limit of 0.04 μg Cu/L was achieved for nCuO.     

Real-Time Measurements of Jet Aircraft Engine Exhaust

Abstract

Particulate-phase exhaust properties from two different types of ground-based jet aircraft engines—high-thrust and turboshaft—were studied with real-time instruments on a portable pallet and additional time-integrated sampling devices. The real-time instruments successfully characterized rapidly changing particulate mass, light absorption, and polycyclic aromatic hydrocarbon (PAH) content. The integrated measurements included particulate-size distributions, PAH, and carbon concentrations for an entire test run (i.e., “run-integrated” measurements). In all cases, the particle-size distributions showed single modes peaking at 20–40nm diameter. Measurements of exhaust from high-thrust F404 engines showed relatively low-light absorption compared with exhaust from a turboshaft engine. Particulate-phase PAH measurements generally varied in phase with both net particulate mass and with light-absorbing particulate concentrations. Unexplained response behavior sometimes occurred with the real-time PAH analyzer, although on average the real-time and integrated PAH methods agreed within the same order of magnitude found in earlier investigations.     

Balancing Riparian Management and River Recreation: Methods and Applications for Exploring Floater Behavior and Their Interaction with Large Wood

River managers are tasked with meeting both ecological and human needs. In the Puget Sound lowland, riparian management often includes placing or allowing the presence of large wood to stabilize riverbanks and enhance salmon habitat. Although this practice benefits humans by protecting infrastructure and natural resources, it is unclear how such practices interact with an additional human interest, recreation. Furthermore, we were unable to find studies that describe how an agency can go about researching the interaction between recreation and large wood management practices. This study tested methods for describing and estimating the number of river floaters, where they float in relationship to river projects, the risks they take while floating, and their perceptions of large wood in the river. Selecting a high-use suburban river in Washington State, we used riverside observations, interviews, and an infrared counter to gather data in the summer of 2010. Statistical analyses provided general characteristics of users, trends in engaging in risky behaviors, and estimates of use for the entire season and on the busiest day. Data mapping with GIS presented the density of use along the river and frequency of use of specific float routes. Finally, qualitative analysis of interviews clarified floaters' perspectives of large wood. To address the multiple mandates of river managers, it is important to understand recreation users, the factors that could be putting them at risk, and how the actual users perceive large wood in the river. This study demonstrates methods for scientifically gathering such information and applying it when making riparian management decisions.     

Elevated carbon dioxide does not offset loss of soil carbon from a corn-soybean agroecosystem

The potential for storing additional C in U.S. Corn Belt soils - to offset rising atmospheric [CO₂] - is large. Long-term cultivation has depleted substantial soil organic matter (SOM) stocks that once existed in the region's native ecosystems. In central Illinois, free-air CO₂ enrichment technology was used to investigate the effects of elevated [CO₂] on SOM pools in a conservation tilled corn-soybean rotation. After 5 and 6 y of CO₂ enrichment, we investigated the distribution of C and N among soil fractions with varying ability to protect SOM from rapid decomposition. None of the isolated C or N pools, or bulk-soil C or N, was affected by CO₂ treatment. However, the site has lost soil C and N, largely from unprotected pools, regardless of CO₂ treatment since the experiment began. These findings suggest management practices have affected soil C and N stocks and dynamics more than the increased inputs from CO₂-stimulated photosynthesis.     

Aerosol speciation and mass prediction from toluene oxidation under high NOx conditions

A kinetically based gas-particle partitioning box model is used to highlight the importance of parameter representation in the prediction of secondary organic aerosol (SOA) formation following the photo-oxidation of toluene. The model is initialized using experimental data from York University's indoor smog chamber and provides a prediction of the total aerosol yield and speciation. A series of model sensitivity experiments were performed to study the aerosol speciation and mass prediction under high NO_x conditions (VOC/NO_x = 0.2). Sensitivity experiments indicate vapour pressure estimation to be a large area of weakness in predicting aerosol mass, creating an average total error range of 70 μg m^?3 (range of 5–145 μg m^?3), using two different estimation methods. Aerosol speciation proved relatively insensitive to changes in vapour pressure. One species, 3-methyl-6-nitro-catechol, dominated the aerosol phase regardless of the vapour pressure parameterization used and comprised 73–88% of the aerosol by mass. The dominance is associated with the large concentration of 3-methyl-6-nitro-catechol in the gas-phase. The high NO_x initial conditions of this study suggests that the predominance of 3-methyl-6-nitro-catechol likely results from the cresol-forming branch in the Master Chemical Mechanism taking a significant role in secondary organic aerosol formation under high NO_x conditions. Further research into the yields and speciation leading to this reaction product is recommended.