Fungal degradation of an acetolactate synthase (ALS) inhibitor pyrazosulfuron-ethyl in soil

Owing to reported phytotoxicity of some sulfonylurea class of herbicides in number of sensitive crops and higher persistence in soil, present study was conducted to isolate and identify pyrazosulfuron-ethyl degrading fungi from soil of rice field. Penicillium chrysogenum and Aspergillus niger, were isolated and identified from rhizospere soil of rice field, as potent pyrazosulfuron-ethyl degrading fungi. Degradation of pyrazosulfuron-ethyl by P. chrysogenum and A. niger, yielded transformation products/metabolites which were identified and characterized by LC/MS/MS. The rate of dissipation of pyrazosulfuron-ethyl was found higher in soil of rice field and soil inoculated with P. chrysogenum. This showed important route of degradation of pyrazosulfuron-ethyl by microbes apart from chemical degradation.     

Development and application of LC–APCI–MS method for biomonitoring of animal and human exposure to imidacloprid

Imidacloprid (IMI) is a relatively new neuro-active neonicotinoid insecticide and nowadays one of the largest selling insecticides worldwide. In the present study a LC–APCI–MS based method was developed and validated for the quantification of imidacloprid and its main metabolite 6-chloronicotinic acid (6-CINA) in urine and hair specimens. The method was tested in biomonitoring of intentionally exposed animals and subsequently applied for biomonitoring of Cretan urban and rural population.     

Measurement of Automobile Exhaust GAS Hydrocarbons

While snowflakes fell and Christmas carols heralded the imminent holiday, over 3000 delegates to the Third National Conference on Air Pollution were told to “Control Now for Clean Air.”

They were told this in many ways by many people—by the Vice President of the United States; by the Secretary of the Department of Health, Education, and Welfare who summoned the Conference; and by senators, congressmen, governors, and mayors.

Then eight panel sessions convened to discuss and to determine how to control now for clean air. Speakers from every section of American life addressed themselves to this subject; when they were finished, the eight session chairmen summarized what had been said, what had been, learned. These summaries appear on the following pages.     

Farm factors associated with reducing Cryptosporidium loading in storm runoff from dairies

A systems approach was used to evaluate environmental loading of Cryptosporidium oocysts on five coastal dairies in California. One aspect of the study was to determine Cryptosporidium oocyst concentrations and loads for 350 storm runoff samples from dairy high use areas collected over two storm seasons. Selected farm factors and beneficial management practices (BMPs) associated with reducing the Cryptosporidium load in storm runoff were assessed. Using immunomagnetic separation (IMS) with direct fluorescent antibody (DFA) analysis, Cryptosporidium oocysts were detected on four of the five farms and in 21% of storm runoff samples overall. Oocysts were detected in 59% of runoff samples collected near cattle less than 2 mo old, while 10% of runoff samples collected near cattle over 6 mo old were positive. Factors associated with environmental loading of Cryptosporidium oocysts included cattle age class, 24 h precipitation, and cumulative seasonal precipitation, but not percent slope, lot acreage, cattle stocking number, or cattle density. Vegetated buffer strips and straw mulch application significantly reduced the protozoal concentrations and loads in storm runoff, while cattle exclusion and removal of manure did not. The study findings suggest that BMPs such as vegetated buffer strips and straw mulch application, especially when placed near calf areas, will reduce environmental loading of fecal protozoa and improve stormwater quality. These findings are assisting working dairies in their efforts to improve farm and ecosystem health along the California coast.     

In situ transmissiometer measurements for real-time monitoring of dust discharge during orchard nut harvesting

Rapid assessments of operating conditions and field preparation on dust discharge from nut harvesters are needed to guide improved equipment design and grower practices for dust reduction. An industrial opacity sensor, typically used for industrial stack monitoring, was adapted for use on a nut harvester to measure relative dust intensity during nut pick-up operations in almond orchards. Due to the high volume of discharge air and the presence of large debris such as leaves, additional components were coupled with the sensor to enable subsampling of the air. Pre-harvest windrow preparation conditions were evaluated. Results indicated that relative dust intensity decreased by 32% during harvest activities after windrow preparation with proper nut sweeper adjustment. Conventional harvesting results indicated that under typical operating conditions, reducing the separation fan speed could reduce relative dust intensity by 54%. Ground speed also had a strong effect; reducing speed from 4.8 to 2.4 km h(-1) reduced opacity of discharged air by 50%. The measurement system was also mounted on a separate vehicle and used as a tool for comparing modifications in harvest machine designs where direct measurement of discharge may not be feasible due to mechanical constraints. A comparison between a conventional harvester and one modification in the harvester design found that the machine modification decreased relative dust intensity by 73%. The measurement tools described in this work can be used to provide rapid feedback on harvester operating conditions, orchard cultural practices, and machine design modifications.     

Sorption and mobility of ivermectin in different soils

Avermectins are widely used to treat livestock for parasite infections. Ivermectin, which belongs to the group of avermectins, is particularly hazardous to the environment, especially to crustaceans and to soil-dwelling organisms. Sorption is one of the key factors controlling transport and bioavailability. Therefore, batch studies have been conducted to characterize the sorption and desorption behavior of ivermectin in three European soils (Madrid, York, and artificial soil). The solid-water distribution coefficient (K(d)) for ivermectin sorption to the tested soils were between 57 and 396 L kg(-1) (determined at 0.1 microg g(-1)), while the organic carbon-normalized sorption coefficients (K(oc)) ranged from 4.00 x 10(3) to 2.58 x 10(4) L kg(-1). The Freundlich sorption coefficient (K(F)) was 396 (after 48 h) for the artificial soil over a concentration range of 0.1 to 50 microg g(-1), with regression constants indicating a concentration-dependent sorption. The obtained data and data in the literature are inconclusive with regard to whether hydrophobic partitioning or more specific interactions are involved in sorption of avermectins. For abamectin, hydrophobic partitioning seems to be one of the dominant types of binding, while hydrophobicity is less important for ivermectin, which is probably due to the lower lipophilicity of the molecule. Furthermore, the presence of cations such as Ca(2+) leads to decreasing sorption. Thus, it is presumed that ivermectin binds to soil by formation of complexes with immobile, inorganic soil matter. In contrast to abamectin, hysteresis could be excluded for ivermectin in the studied soils for the evaluation of sorption and desorption. The sorption mechanism is highly dependent on physicochemical properties of the avermectin.     

A framework for valuing the health benefits of improved bathing water quality in the River Irvine catchment

A simple model predicting bathing water concentrations of Escherichia coli from livestock in the Irvine catchment in SW Scotland has been adapted for intestinal enterococci (IE). This has been used to predict risk of bather illness by extrapolation of published data on bather IE exposure vs incidence of gastro-enteritis. Simulated reduction in the risk of illness by reduced faecal loading was multiplied by a willingness to pay for risk reduction to estimate the annual benefits of mitigation. Health benefits of reducing loading by 75% at Irvine Beach were estimated by a willingness to pay method to be about pound 276k pa. Estimated annualised costs of diffuse pollution mitigation measures across the catchment were higher (> pound 1m), and it is very unlikely that 75% mitigation is achievable with current stocking rates. Further work should explore the influence of uncertainty of model parameters, and use emerging epidemiological information on specific zoonotic pathogens such as E. coli O157 and Cryptosporidium. Other components of the value of clean water should also be included to obtain a complete estimate of the cost:benefit of mitigation.     

Sustainability, substance flow management and time. Part I Temporal analysis of substance flows

Flows of chemical substances need to be managed in a sustainable way. Sustainable development as a whole and the sustainable management of substance flows in particular are both time issues. These include the importance of the dynamics of substance flows and the way these interconnect with the use of resources, the avoidance of environmental pollution, and their effects on health and food production. Another prerequisite for the proper management of substance flows is justice within and between generations. This requires a systematic approach and a systematic analysis of the issues as well as of the actions to be taken. One tool for such a systematic approach is temporal analysis. It brings the temporal aspects of the substances themselves and of their intended use, as well as factors affecting the stakeholders, such as decision makers, producers and consumers, into focus. In the past, timing factors were rarely taken into account. Knowledge of the temporal dynamics of substance flows and their resultant outcomes, as well as of their interaction with ecological, economic and social systems, is a basic requirement for successful substance flow management. The need to include temporal aspects into substance flow management and how to do so is outlined here. Included are not only politicians but also practitioners and scientists who must explicitly take into account adequate time scales, points in time, breaks and other forms of time in planning and acting.     

Should Habitat Trading Be Based on Mitigation Ratios Derived from Landscape Indices? A Model-Based Analysis of Compensatory Restoration Options for the Red-Cockaded Woodpecker

Many species of conservation concern are spatially structured and require dispersal to be persistent. For such species, altering the distribution of suitable habitats on the landscape can affect population dynamics in ways that are difficult to predict from simple models. We argue that for such species, individual-based and spatially explicit population models (SEPMs) should be used to determine appropriate levels of off-site restoration to compensate for on-site loss of ecologic resources. Such approaches are necessary when interactions between biologic processes occur at different spatial scales (i.e., local [recruitment] and landscape [migration]). The sites of restoration and habitat loss may be linked to each other, but, more importantly, they may be linked to other resources in the landscape by regional biologic processes, primarily migration. The common management approach for determining appropriate levels of off-site restoration is to derive mitigation ratios based on best professional judgment or pre-existing data. Mitigation ratios assume that the ecologic benefits at the site of restoration are independent of the ecologic costs at the site of habitat loss. Using an SEPM for endangered red-cockaded woodpeckers, we show that the spatial configuration of habitat restoration can simultaneously influence both the rate of recruitment within breeding groups and the rate of migration among groups, implying that simple mitigation ratios may be inadequate.