ISSN:0265-203X    

DOI:10.1080/026520300412357

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The observed phenomenon of variability of residues in individual fruit and vegetables has a number of implications for risk assessment. The main implication is that the possibility of acute toxic effects in humans has to be considered, where items are commonly consumed unprocessed, are commonly consumed at a single sitting and the pesticide involved has substantial acute toxicity. The main groups of pesticides of concern are the anticholinesterase organophosphates and carbamates. The problem partly arises from the fact that, with some older pesticides, studies of the type most appropriate for setting acute reference doses (ARfDs) have not been carried out. As a result ARfDs are based on studies of length that is greater than ideal. While there is little evidence from the scientific or medical literature that food-borne pesticide poisoning is occurring on any major scale, the symptomatology of such poisoning would be non-specific and the pattern in the population, sporadic. Hence it is likely that pesticide-related illness, through food, would be missed. It is concluded that risk assessments should be improved, using refined safety factors, more appropriate studies and better intake data. The reasons for the variability could be sought and remedied or the application conditions of the pesticide modified.

ISSN:0265-203X    

DOI:10.1080/026520300412366

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

As a result of routine monitoring data on carrots generated in the 1990s indicating MRL exceedances, further studies showed that residues of organophosphorus compounds in individual roots could vary up to 25 times the levels found in composite samples. Additional work found that this phenomenon also extended to other crops including apples, peaches and celery. Variability (defined as the highest residue level found in any one crop item divided by the level found in a composite sample from the same batch) of up to 34 times mean values was found in one batch of plums. Conventional deterministic methods used in consumer assessments were likely to give gross overestimates of short-term exposure because of the assumptions employed. This led to the development of probabilistic models which made the best use of all available information and was capable of indicating percentages of consumers that could exceed relevant toxicological end points. This indicated that there was unlikely to be serious health effects as a result of ingesting these residues and has subsequently proved to be a useful aid to regulatory decision making.

ISSN:0265-203X    

DOI:10.1080/026520300412375

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The evolution of US Environmental Protection Agency's (EPA) process for estimating potential health risks from pesticide residues in or on food is examined in light of changes in US Legislation and the variability of residue data and assumptions used to estimate dietary exposure. In the 86 years since enactment of the Insecticide Act, pesticide laws have become progressively more health-based. Passage of the 1996 Food Quality Protection Act (FQPA) requires EPA to place particular emphasis on assessing potential risk from pesticides to infants and children. Primary factors affecting the actual pesticide residues in food include frequency of application, percentage of crop treated, and the interval from treatment to harvest. Primary factors affecting the estimated pesticide residues in food include the source of the residue data, calculation techniques for non-detected residues, and the availability of data reflecting post-harvest treatments. Risk assessors must thoroughly consider these factors when assessing dietary risk to pesticides. Risk managers will need to consider these factors as a means of mitigating dietary risk from pesticides.

ISSN:0265-203X    

DOI:10.1080/026520300412384

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

A pilot study was established to determine whether the preferential flow of water and thus insecticide in carrot beds might be responsible for the high residues of organophosphorus insecticides detected in individual carrot roots grown in the UK. A field site typical of UK carrot growing conditions was selected on a sandy soil with a low organic carbon content. Brilliant blue dye was applied in water to a small number of field plots located in the carrot beds to trace water movement through the bed and not to simulate insecticide application or irrigation. The plots were excavated following sufficient time for infiltration and drainage. Horizontal and vertical cross-sections through the soil profile were cut and descriptions of the dye presence in relation to soil features and the position of the carrot roots were made. Dye tracing and soil analyses showed there was a clear mechanical cultivation effect which generated a preferential movement of dye and water within the bed. The subsequent growth of carrots also created additional pathways of preferential movement due to stemflow or canopy drip. A second study which increased replication of samples and allowed analysis of triazophos and chlorfenvinphos residues in the carrots could not identify any single factor which was conclusively responsible for initiating high residues in individual roots.

ISSN:0265-203X    

DOI:10.1080/026520300412393

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

In relation to residue variability and acute dietary intake, this paper considers whether or not consumers are adequately protected, and makes recommendations for governments and international bodies. Existing risk assessment science is inadequate to lay to rest some concerns raised by the scientific community, and it is plausible that acute exposures to pesticides from the most contaminated food may be causing adverse effects in some consumers. Consumers International recommends that: (1) analysis and regulation of pesticides with a common mechanism of action (e.g. organophosphate insecticides) be conducted in an integrated, aggregated manner, not on a single pesticide basis; (2) exposure to pesticides in foods consumed in large amounts by children be reduced by revising good agricultural practices; (3) clear risk assessment policies for acute risk assessments be established at the national and international level; and (4) an additional safety factor be applied in order to protect children when establishing maximum residue limits (MRLs) for pesticides in the absence of reliable data on the effects of pesticides on children (e.g. no pesticide-specific tests on immature animals for effects on the developing brain, endocrine, or immune systems).

ISSN:0265-203X    

DOI:10.1080/026520300412401

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Information on the variability of residues in individual fruits and vegetables is required to estimate the acute dietary exposure to pesticides. The distribution of residues in apples, kiwi fruits, potatoes and butter beans was studied in field experiments representing commercial farming practice. No correlation was found between the residue concentration or surface residue and the mass of apples. The relative frequency distributions of residues in crop units were continuous and skew positive. The log-normal transformation did not result in a normal distribution in any of the trials. Consequently, 299, 120 and 59 random samples should be analysed to estimate 99th, 97.5th and 95th percentile of the residues at 95% confidence level. The distribution of residues is not significantly influenced by the mean residue, pre-harvest interval, chemical and physical properties of the active ingredient, formulation of pesticide or, on top fruit, the foliar application method. However, the residue distribution is likely to be influenced by the size, shape and density of the plants, and mode of application of pesticides. The variability factor should be defined as the ratio of the highest value at a specified percentile of residues occurring in unit crops and the population mean. Generic variability factors may be determined for various groups of commodities. Variability factors of 5 and 9 are recommended for medium size fruits, and potato following granular application of pesticides, respectively.

ISSN:0265-203X    

DOI:10.1080/026520300412410

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

Data generated in the UK have indicated that pesticide residue levels can be highly variable between the individual fruit or vegetables from the same crop or lot in trade. Statistical experiments with these data showed that residues in composite samples, taken according to Codex recommendations, are unlikely to differ by more than a factor of 3–4 from the mean level in the lot. This was corroborated by results obtained from real composite samples. Many fruit or vegetables in trade are mixed after harvest to form combined lots. Analysis of composite samples provides a good indication of average residues but, where the lot has been mixed, such average values are potentially misleading. Residues monitoring is the best means available for general control of pesticide use and consumer exposure, but new strategies for sampling and analysis are required to address the combined effects of residues variability and mixing of lots.

ISSN:0265-203X    

DOI:10.1080/026520300412429

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The method used to take samples for residues testing in Sweden involves taking three subsamples of 1–2kg. These are split in two for laboratory analyses. Where required one of these laboratory samples can be used to determine the variability between individual units. Details of the variation in residues in individual units of a number of commodities are presented. The highest variability factors, around 600, expressed as the quotient of the maximum and the minimum residue, were found for methamidophos in peppers and monocrotophos in grapes.

ISSN:0265-203X    

DOI:10.1080/026520300412438

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor

摘要:

The Codex Committee on Pesticide Residues (CCPR), in its development of international standards, has been considering during the last few years the implications of residues of acutely toxic pesticides in food commodities. CCPR has asked its scientific advisory body, the Joint FAO/W HO Meeting on Pesticide Residues (JMPR), for advice on the safety of the standards that are being developed. This work began in 1993. The 1994 JMPR first decided to use the ‘acute reference dose’ as a toxicological benchmark for a ‘short-term ADI’. A number of acute reference doses have been allocated at subsequent meetings. The 1998 JMPR decided to consider the allocation of an acute reference dose whenever a full evaluation of a pesticide is undertaken. General guidance for the allocation of an acute reference dose was provided by the 1998 JMPR, which is discussed in this paper.

ISSN:0265-203X    

DOI:10.1080/026520300412447

出版商:Taylor & Francis Group    

年代:2000

数据来源: Taylor