ELISA AND GC/MS ANALYSIS OF PESTICIDE RESIDUES IN NORTH CAROLINA1

ABSTRACT: Studies were conducted to analyze the presence of 11 pesticide residues in 12 surface waters in the Piedmont and coastal plain regions of North Carolina. Samples were assayed using enzyme‐linked immunosorbent assays (ELISAs). All ELISA results of one part per billion (ppb, μg/L) or greater were confirmed using gas chromatography/mass spectrometry (GCIMS). ELISA detection limits were approximately an order of magnitude higher than GCJMS methods. Of the 5,035 analytical results from 742 surface water samples, atrazine was detected in approximately 45 percent of the samples, five of which were at or above the Maximum Contaminant Level (MCL) of 3‐ppb. Metolachlor was detected in 64 percent of the samples. Aldicarb, 2,4‐D, chlorpyrifos, and chlorothalonil were also detected, and each was found in less than 12 percent of the samples. The remaining pesticides, including carbaryl, acetochior, methomyl, carbofuran, and alachlor, were not detected during the study period.     

Consumer attitudes regarding environmentally sustainable wine: an exploratory study of the New Zealand marketplace

Previous research has suggested that consumers are becoming increasingly concerned by the effects of conventional agricultural food production practices on human health and environmental wellbeing. This study sought to understand whether environmentally sustainable practices in the vineyard would equate to advantages in the wine marketplace. Structured questionnaires were used to ascertain the views of wine consumers in Christchurch, New Zealand. The findings of this study indicate that consumers have a strong demand for wine which is produced using “green” production practices. Consumers believe that the quality of sustainable wine will be equal to or better than conventionally produced wine, and they are prepared to pay a higher price for this wine.     

The impact of invasive aquatic plants on ecosystem services and human well-being in Wular Lake,India

Regional Environmental Change - Alien invasive species cause significant impacts on ecosystems and economies, but the impacts on human well-being and livelihoods are less well known. Negative...     

Experimental Rock Outcrops Reveal Continuing Habitat Disturbance for an Endangered Australian Snake

Abstract: Protected areas are commonly viewed as safe havens for endangered species. To test this notion, we experimentally constructed small rock outcrops for the endangered broad-headed snake (   Hoplocephalus bungaroides ) within a national park near Sydney, Australia. Rock outcrops provide vital shelter sites during the cooler months of the year. Constructed rock outcrops (3 × 5 m) were placed at 11 paired sites located near (≤250 m) and far from (>400 m) walking tracks and roads. Eight of our 22 rock outcrops were disturbed by people over a 15-month period. Disturbance consisted of displacement of some rocks or complete destruction of the outcrop. Disturbed outcrops occurred up to 450 m from a walking track or road. Disturbance to natural outcrops has also been observed in this park. This demonstrates a continuing decline in the quality of this snake's habitat. Twenty of our rock outcrops were colonized by velvet geckos ( Oedura lesueurii ), the primary prey of this snake. One broad-headed snake was found in one outcrop. According to these findings, attempts to restore the habitat of this endangered snake should be centered on sites located ≥500 m from a walking track or road. Our study highlights the value of targeted experiments that precede larger-scale habitat restoration.     

Polymer and invert emulsifying oil effects upon droplet size spectra of sprays

Abstract

A series of wind tunnel atomization studies were carried out to investigate the effects of polymer and invert suspension oil “drift control adjuvants” upon the droplet size distribution spectra produced by nozzles typically used in aerial and ground based spraying of pesticides. A D8–46 disc and core was used as a typical aerial application nozzle, and an 8003 fan nozzle was used for the ground based sprayers simulation. The droplet size spectra were evaluated in a wind tunnel using a Malvern 2600 laser particle size analyzer immediately upon mixing and at 15 minutes after re‐circulation through a pumping system. The addition of the polymer‐based adjuvants significantly increased the droplet size spectra parameters of the spray cloud, but all the polymer products showed signs of breakdown of their molecular arrangements in the liquid medium, as a result of agitation. The invert suspension oil adjuvant did not change the droplet size spectra markedly, nor did it show signs of breakdown of the internal liquid structure after re‐circulation.     

Effects of sublethal concentrations of isoxaben on the development of the African clawed frog,Xenopus laevis

Agricultural pesticide exposure is one factor implicated in the decline of amphibian abundance in aquatic ecosystems. Isoxaben is a cellulose biosynthesis inhibitor mainly used for roadside weed control, suggesting that isoxaben can run off during rain events and potentially affect amphibian development. This study followed the development of African clawed frog (Xenopus laevis) tadpoles exposed to different environmentally relevant concentrations of isoxaben. No significant adverse effects were observed on days to metamorphosis or size and weight at metamorphosis. This reinforces the conclusion that isoxaben herbicide application at low environmental concentrations is not a substantial risk to wildlife.     

Costs and carbon emissions for geopolymer pastes in comparison to ordinary portland cement

Geopolymer concrete is seen as a potential alternative to standard concrete, and an opportunity to convert a variety of waste streams into useful by-products. One key driver in geopolymer development is the desire to reduce greenhouse gas emissions from the production of concrete products. This paper presents an examination of the lifecycle cost and carbon impacts of Ordinary Portland Cement (OPC) and geopolymers in an Australian context, with an identification of some key challenges for geopolymer development. The results of the examination show that there is wide variation in the calculated financial and environmental “cost” of geopolymers, which can be beneficial or detrimental depending on the source location, the energy source and the mode of transport. Some case study geopolymer concrete mixes based on typical Australian feedstocks indicate potential for a 44–64% reduction in greenhouse gas emissions while the financial costs are 7% lower to 39% higher compared with OPC.     

PESTICIDE ACCUMULATION IN A NEW IMPOUNDMENT IN IOWA1

ABSTRACT: Estimates were made of the amounts of selected pesticides entering and leaving Saylorville Reservoir, a new partly filled impoundment on the Des Moines River. Samples were collected at 1– or 2-week intervals at stations above, in, and below the reservoir. Atrazine, alachlor, and cyanazine were found only in the dissolved state, and dieldrin and p, p′ -DDE in both the, dissolved and suspended state. Heptachlor epoxide, p,p-DDT. p, p′ -DDD, 2,4-D, 2,4,5-TP, endrin, lindane, methoxychlor, propachlor, and toxaphene were not detected or were at very low concentrations. Estimated deposition in the reservoir from September 1977 to October 1978 was 281 kg atrazine, 251 kg alachlor, 26 kg cyanazine, 16 kg dieldrin, and 20 kg p, p′ -DDE.