Plant Biomarker Pattern, Apples grown with various availability of organic nitrogen and with or witout the use of pesticides

In the recent years there has been an increasing focus on the quality and health value of organic plant products compared with conventional products. The use of pesticides and concentrated fertilisers in conventional agriculture implies a risk of effects on plant composition, which may affect health of the consumer (Brandt & Mølgaard, 2001). To determine if organically grown plant food could provide more or less benefits to health than conventional food, a first step is to investigate the differences in the composition and relative concentration of natural compounds in the plant products. In this project apples were grown with two levels of nitrogen availability and with or without the use of pesticides. The apples were screened for changes in the phytochemical composition and concentration. The work is affiliated to the project "Organic food and health" supported by the Danish Research Centre for Organic Farming (DARCOF). Biomarkers and biomarker patterns were presented in plants cultivated with low and high N and with pesticides. One biomarker was related to: • the type of N with and without pesticides • pesticides at high N and type of N without pesticides • pesticides at low and high N One biomarker pattern was related to: • the type of N • the type of N without pesticides • pesticides at low N and type of N without pesticides • pesticides at high N and type of N with pesticide

Evaluating health risks from occupational exposure to pesticides and the regulatory response.

In this study, we used measurements of occupational exposures to pesticides in agriculture to evaluate health risks and analyzed how the federal regulatory program is addressing these risks. Dose estimates developed by the State of California from measured occupational exposures to 41 pesticides were compared to standard indices of acute toxicity (LD50) and chronic effects (reference dose). Lifetime cancer risks were estimated using cancer potencies. Estimated absorbed daily doses for mixers, loaders, and applicators of pesticides ranged from less than 0.0001% to 48% of the estimated human LD50 values, and doses for 10 of 40 pesticides exceeded 1% of the estimated human LD50 values. Estimated lifetime absorbed daily doses ranged from 0.1% to 114,000% of the reference doses developed by the U.S. Environmental Protection Agency, and doses for 13 of 25 pesticides were above them. Lifetime cancer risks ranged from 1 per million to 1700 per million, and estimates for 12 of 13 pesticides were above 1 per million. Similar results were obtained for field workers and flaggers. For the pesticides examined, exposures pose greater risks of chronic effects than acute effects. Exposure reduction measures, including use of closed mixing systems and personal protective equipment, significantly reduced exposures. Proposed regulations rely primarily on requirements for personal protective equipment and use restrictions to protect workers. Chronic health risks are not considered in setting these requirements. Reviews of pesticides by the federal pesticide regulatory program have had little effect on occupational risks. Policy strategies that offer immediate protection for workers and that are not dependent on extensive review of individual pesticides should be pursued

The half-lives of biological activity of some pesticides in water

In the absence of analytical methods, the half-lives of biological activity of pesticides can be estimated by bioassays. To determine the half-lives of biological acivity of pesticides to fish, static bioassays were conducted in the laboratory with ten different formulations of pesticides using Labeo rohita as a bio-indicator. The half-lives of biological activity for ten different pesticides in soft water at pH 7.5 and 27°C, ranged from 4.6 days to 11.8 days. The half-life of biological activity of Sumithion 50% EC was only 4.6 days. In contrast, Dimecron 50% EC degraded very slowly and its half-life of biological activity on L. rohita was about 11.8 days. Sumithion 50% EC, Padan 50% SP, EPN 45% EC, Diazinon 40% EC and Diazinon 10 G degraded in less than five to seven days indicating that these pesticides are desirable for rice-fish culture. Contamination by pesticides with long-term residual toxicity in waters may eventually cause high levels of fish mortality

Influence of Rice Production on the Quality of Water in Tailwater Collection Reservoirs

Since maintaining high water quality standards in the state remains a high priority, monitoring for pesticides in water sources must continue. Determining the type, concentration, and characteristics of any pesticides present in water supplies are essential to the overall assessment of water quality. Five independent locations, implementing contained water management systems and recyclable water, were monitored in 1995 and 1996. Irrigation, runoff, and pond water samples were collected every 10 to 14 days between permanent flood establishment and draining. Water samples were transported to the laboratory and extracted for 16 pesticides using solid phase extraction (SPE) techniques. Quantification and confirmation of pesticide residues were obta1ned by HPLC and GC/MS analysis. The lower limit of quantitation for all pesticides was between 1.0 -1.3 pg L-1 in water. Pesticides selected for monitoring were determined after assessing state recommendations and our analytical capabilities. Pesticides included: benomyl, bensulfuron methyl, carbaryl, carbofuran, 2,4-D, fenoxaprop ethyl, propiconazole, malathion, MCPA, methyl parathion, molinate, pendimethalin, propanil, iprodione, quinclorac, triclopyr, and thiobencarb. Since each field location was independently managed, individual results are site specific. 2,4-D, benomyl, molinate, propanil, quinclorac, thiobencarb, and pendimethalin were the pesticides actually applied during the seasons. These pesticides were detected, usually at trace levels, in tailwaters shortly after application but did not appear to buildup in the reservoirs. Quinclorac residues in the tailwaters were more persistent (up to 8 weeks) than the other detected compounds (less than 2 weeks)

Insecticide Effects on Normal Development and Hatch of Embryos of \u3ci\u3eParatanytarsus Parthenogeneticus\u3c/i\u3e (Diptera: Chironomidae)

Simple, low cost methods are needed to determine the effect of pesticides on non-target aquatic organisms. In this report, embryos of Paratanytarsus parthenogenetic us were exposed from deposition to hatch to five pesticides. Four of the five pesticides affected development or hatch only at concentrations which exceeded 96-h LC50 values of other non-target invertebrates. One pesticide, fenitrothion, affected hatch at 13 Ilgll which is similar to 96-h LC50 values for other aquatic invertebrates. Because of the low sensitivity of the embryo to pesticides, this method may not be a useful pesticide screening test for non-target invertebrates

Federal Regulation of Pesticide Residues: A Brief History and Analysis

In the United States today, there are over 900 pesticides in use1 and over 400 are approved for use in food production, whether used as part of the growing process or in post-harvest handling. Although the history of pesticide use in food crops goes back centuries, the post-war period has seen an enormous growth in the varieties and amounts of pesticides used in our food system. As our reliance on pesticides has grown, pesticides have become a divisive issue. Pesticide advocates view them as essential to a secure and reliable food supply needed to feed a growing world population. Detractors, however, point out the public health risks—both known and not yet fully understood—that widespread pesticide use may entail. Meanwhile, consumer demand for products grown without the use of pesticides is increasing, while at the very same moment farmers are applying more and different pesticides to combat pesticide-resistant “superweeds.” These tensions are playing out both globally and locally in a variety of arenas, from debates over pesticide bans within international organizations and national governments, to the litigation of personal injury claims in American courts

Politics of pesticides

In regard to pesticides, today we have lost the benefit perspective. We no longer have a balance in the mind’s eye of the media, nor in the mind’s eye of the public as a whole. We talk, instead, about the risk to man, the risk to the environment, and the risk to wildlife that is wrought by the very use of the modern tools that have brought up production and health protection miracles. And, until that perspective is re-asserted in a balance, we’re going to lose the very tools that we depend on today to produce quality food, economical fiber, and to protect the good health of this nation. It’s amazing to me that we can ban the use of ethylene dibromide (EDB) and restrict its contamination in ready-to-eat products to 30 ppb, when at the same time we allow aflatoxin, which is a mold in peanut butter, to be present at 15 ppb knowing full well that it has 1,000 times the carcinogenic potential of EDB. That is the consistency and logic of our federal government. We need to re-align perception with fact, because unless we do and until we do, the politics of pesticides are going to win

Determining Pesticide and Nitrate Levels in Spring Water in Northwest Arkansas

Occurrences of pesticides in our nations ground water are on the rise. As states become aware of this problem and begin monitoring programs, incidence of contamination will probably increase. Since the problem of pesticides in groundwater is relatively new, little research has centered on the fate of pesticides after they reach the groundwater environment. In Northwest Arkansas efforts to monitor groundwater for pesticides have been small. Twenty-five springs in Northwest Arkansas were sampled in the fall of 1988, and spring of 1989. Analysis for atrazine, alachlor, metolachlor, diuron, and simazine in spring water was preformed using gas liquid chromatography and high performance liquid chromatography. No detectable residues of any of the selected pesticides were found. Northwest Arkansas is a leader in poultry production. Much of the manure from poultry houses is spread on the sourounding pastures. As this litter decomposes nitrates and phosphates are released. Nitrate and phosphate concentrations were also determined on water from the spring samples. No spring exceeded the EPA\u27s limit of 45 mg/L for nitrate in drinking water. The highest concentration for phosphate in any spring was 1.05 mg/L