Assessing the risks of pesticide residues to consumers: recent and future developments

Assessing exposure of consumers to pesticide residues is an area of regulatory science that has rapidly developed over the last decade. From simplistic, deterministic models calculating lifetime exposure for adults only, assessment procedures have diversified so that more realistic estimates of long term exposures for adults, schoolchildren, toddlers and infants and short term exposures for adults and toddlers (who generally bound the more extreme consumer patterns) are now carried out. The final assessment of risk still remains a simplistic numeric comparison against hazard assessment based on a wide range of toxicity studies incorporating the appropriate safety or uncertainty factors. As development of risk assessments continues, the use of probabilistic models is becoming an invaluable information tool for quantitative risk management and aiding assessment of cumulative exposure. This paper examines the recent developments in risk assessment and consumer perception of the risks of pesticide residues, and speculates where the future developments in these areas may lie.     

Pesticide residues variability and acute dietary risk assessment: a consumer perspective

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).     

Occurrence of heterocyclic aromatic amines in the Swiss diet: analytical method, exposure estimation and risk assessment

A total of 86 meat samples, prepared in restaurants or homes, ready to eat (including poultry and fish) and 16 commercial samples such as bouillon (cubes) were analysed for heterocyclic aromatic amines (HAA). The analytical method consisted of an acidic extraction, clean-up on a cation exchange cartridge followed by an analogous HPLC step to recover the following HAA: IQ, MeIQ, MeIQx, 4,8-DiMeIQx, PhIP and 7,8-DiMeIQx. The HAA containing HPLC-fractions were collected, the HAA identified and quantified using two RP-HPLC-systems of different retention properties (UV-detection). The limit of quantitation was in the range of 0.2-0.4ng/g and the relative repeatability 6-15%. The recovery of PhIP was lower than for the other HAA analysed (less than 80%) and a correction factor was applied. No significant differences of the HAA-concentration were found in samples from homes and restaurants. half of the total samples contained HAA at the following frequencies: PhIP and MeIQx 33% (each), 4,8-DiMeIQx 11% and MeIQ 4%; 7,8- DiMeIQx and IQ were not detected. The frequencies in commercial products were for MeIQx 31%, 7,8- DiMeIQx 19%, IQ 13% and PhIP 6%; MeIQ and 4,8-DiMeIQx were not found. Based on these data, the average exposure of Swiss adults to HAA was estimated to be 5ng/kg body mass per day, commercial products contributing less than 10%. The theoretical excess cancer risk due to this intake was estimated on the base of the carcinogenic potency of the HAA in long-term animal experiments by linear extrapolation. The resulting risk in the order of 10^-4 at the maximum is discussed in terms of Swiss epidemiological data.     

Exposure assessment of dioxins/furans consumed in dairy foods and fish

Dioxins/furans are ubiquitous environmental contaminants whose primary route of human exposure occurs via the consumption of fatty foods of animal origin. The US FDA conducted a market basket survey of dairy products and commercial fish and shellfish to obtain data on levels of 17 dioxin/furan congeners (2, 3, 7, 8- congeners) in the US. The dairy products sampled included various cheeses (American, cheddar, Swiss, cottage), ice cream, yogurt, butter, and milk. The finfish and shellfish (molluscs and crustacea) sampled are those marine species consumed in the greatest amounts and include canned tuna, shrimp, cod, blue crab, and oysters. Catfish was sampled because it is the dominant aquaculture species. Samples were collected in 1995/96 and analysis for 17 dioxin/furan congeners was performed by high-resolution gas chromatography following extraction and clean-up. Limits of detection (LOD) and quantitation (LOQ) for each congener in each food were reported. Point estimates of exposure were calculated using a 3-day (1-day diary plus 2-day recall) food consumption survey for eaters-only and for the general population (USDA/CSFII, 1989-92). Toxicity equivalency factors (TEFs) developed by the World Health Organization (1997) were used to derive overall dioxin/furan toxicity equivalents (TEQ) for each sample food. Mean estimates of TEQ exposure for each food were derived using five values for nondetects (ND 0; ND 1/2 LOD or LOQ; ND = = = LOD or LOQ) on both a total sample and eaters-only basis. Using zero and the LOD provide lower and upper bounds on the range of estimated exposure, respectively. The bounds on mean dioxin intakes (pg/person/ day) calculated for consumers of specific foods were estimated as follows (using zero or LOD for nondetects): butter (0.5-11), cheese (1.6-3.2), ice cream (4-19), yogurt (0.8-28), catfish (148-150), fish (other than catfish) (0.03-9), crustacea (32-35), mollusks (16.1-16.6), and shrimp (0.09-4.5). Exposure estimates derived by the five ND-methods are strongly dependent on the LOD and LOQ and represent upper bound estimates of exposure. Uncertainty in the exposure estimates is reduced with refinements in the analytical method.     

A quantitative risk assessment for fumonisins B1 and B2 in US corn

Quantitative risk analysis permits modifying risk estimates with changes in variables such as exposure. This analysis for exposure to the mycotoxin fumonisin describes the magnitude of adverse effects, variability in the population and uncertainty of models as a range of possible outcomes. The most sensitive adverse response in rats, nephrotoxic lesions, was used for the dose-response analysis. Dietary intake of corn products was estimated from a 3-day consumption survey. Levels of corn in each product were estimated by standard methods. Fumonisin levels in corn products were estimated from Food and Drug Administration (FDA) surveillance data and distributions of fumonisin consumption were modelled for each eater in the survey population. Uncertainty for predictions made from each model and uncertainty resulting from model selection were described. Results of the dose-response and exposure analyses were assimilated in a two-dimensional Monte-Carlo simulation. Distributions representing variability and uncertainty were iteratively selected to form an array of estimates of the risk. On the basis of this analysis, current dietary levels of fumonisin would not result in renal lesions even at upper levels of exposure. To avoid toxicity at much higher doses, limiting corn intake would be more effective than would limiting the level of fumonisin in corn.     

Stability in consumer responses to familiar and new chocolates during a period of exposure

The aim of this paper is to study the effects of exposure to different types of chocolate on consumer responses. Three different chocolates were considered, one established market leader and two new chocolates from a product development project. A group of consumers participated two times in a central location test and were exposed to different chocolates over a 4 weeks period between the two occasions. Main focus is on informed liking with the inclusion of brand name. Both average effects and individual differences in consumers’ responses are discussed. The main conclusion of this study is that the liking of the established chocolate was similar before and after exposure (with a slight decrease in liking) while the liking went significantly up for one of the new products.     

Tetracycline residues in meat and bone meals. Part 1: Methodology and examination of field samples

The incidence of tetracycline residues in commercially available samples of meat meals and meat and bone meals was investigated. Four different methods were used on each of the 87 samples from nine different rendering plants in Germany: examination using a screening fluorescence test; examination by high performance liquid chromatography analysis using three different extraction procedures (succinate buffer, hydrochloric acid, hydrochloric acid after sedimentation of bone particles). Tetracyclines were found in 100% of the samples by one or more of the extraction procedures. The highest concentrations found in meat meals were 2048 microgkg(-1), 1393 microgkg(-1) and 608 microgkg(-1) for oxytetracycline, tetracycline and chlortetracycline, respectively. In meat and bone meals the highest concentrations were 2295 microg oxytetracycline kg(-1) 848 microg tetracycline kg(-1) and 1274 microg chlortetracycline kg(-1). The extraction after sedimentation was the most effective of the applied extraction procedures and exposed the highest total tetracycline concentrations. The results of this investigation showed that considerable amounts of tetracyclines have to be expected in field samples. Further research has to be done on the heat stability of bound tetracycline residues.     

Cumulative risk assessment of the intake of organophosphorus and carbamate pesticides in the Danish diet

The aim of the study is to evaluate the potential cumulative effects of organophosphorus and carbamate pesticides that act through a common mechanism of toxicity, and to assess the long- and short-term risks for the Danish population. The intake estimates are based on dietary intake data collected in the Danish nation-wide food consumption survey in 1995. The pesticide data are based on the Danish pesticide residue-monitoring programme from 1996-2001. The amount of 35 organophosphorus pesticides and carbamates were included in the cumulative risk assessment. Processing factors, such as reduction of pesticide levels by rinsing and peeling, were applied in the exposure assessment. The "Toxicity Equivalence Factor" (TEF) approach was used to normalise the toxicity of the different organophosphorus and carbamate pesticides. Cumulative chronic exposure of organophosphorus and carbamates pesticides via fruit, vegetables and cereals is for adults 0.8-2% of the Acceptable Daily Intake (ADI) in chlorpyrifos equivalents, and 0.03-11% of the ADI in methamidophos equivalents; and for children 2-5% of the ADI in the chlorpyrifos equivalents, and 0.07-27% of the ADI in methamidophos equivalents. Neither Acute Reference Dose (ARfD) nor ADI was exceeded for any of the compounds studied. The results indicate that the Danish population is neither exposed to any cumulative chronic risk, nor at risk of acute exposure, from consumption of organophosphorus and carbamate pesticides from fruit, vegetables and cereals.     

Dietary exposure to trace elements and health risk assessment in the region of Valencia,Spain: a total diet study

ABSTRACT

Dietary exposure of the Valencian region population to lead, cadmium, inorganic arsenic (iAs), chromium, copper, tin and methylmercury (meHg) was assessed in a total diet study carried out in the region of Valencia in 2010–11. A total of 8100 food samples were collected and analysed. Occurrence data were combined with consumption data to estimate dietary exposure in adults (> 15 years of age) and young children (6–15 years of age). The estimated intake was calculated by a probabilistic approach. Average intake levels (optimistic scenario) for lead, iAs, chromium and tin were 0.21, 0.08, 1.79 and 1.87 µg kg^?1 bw day^?1 respectively; for Cd and meHg average intake levels were 0.77 and 0.54 µg kg^–1 bw week^?1, respectively, and for Cu, 1.60 mg day^?1. In terms of risk characterisation, the results showed that 2.84% of the adult population may exceed the BMDL₁₀ (benchmark dose lower confidence limit) established for Pb, which is linked to renal effects; whereas 28.01% of the young children population may exceed the BMDL₀₁ related to neurodevelopment effects. In addition, 8.47% of the adult population and 12.32% of young children exceeded the meHg tolerable weekly intake (TWI).     

Tetracycline residues in meat and bone meals. Part 2: The effect of heat treatments on bound tetracycline residues

The stability of bound tetracycline residues during heat treatments at 133°C and 100°C for up to 45min was investigated. An intermediate product from a rendering plant was mixed with bone splinters that contained bound tetracycline (TC) and chlortetracycline (CTC) residues. The mixture was heated in an auto-clave at 133°C for 20, 30 and 45min and at 100°C for 20 and 30 min and subsequently dried at 103°C for 4 h. Two different extraction procedures with hydrochloric acid were used, one with and one without the previous sedimentation of bone particles. Tetracycline concentrations were determined by HPLC analysis before and after the heat treatment. A complete destruction of tetracyclines during heat treatment at 133°C could not be demonstrated, but there was a significant decrease of TC by about 50%. CTC was less resistant to the same temperature, which brought about a reduction of 90-100% . Treatments at 100°C did not bring about any reduction, except for CTC after extraction without sedimentation. The possible toxicological relevance of the findings is discussed. Further research has to be done on possible degradation products of the tetracycline derivatives.     

Measurements of lycopene contents in fruit: A review of recent developments in conventional and novel techniques

Lycopene is a biologically active phytochemical reported in fruit. Conventional techniques such as high performance liquid chromatography (HPLC) and thin layer chromatography (TLC) have been in existence for measuring lycopene in fruit, but these methods are destructive with relative accuracy and speed. Other novel spectroscopic and imaging approaches, which are more reliable and fast, have recently been developed to investigate complex components such as lycopene, total soluble solids, etc. in fruit. The current review attempts to highlight the potential of both conventional and novel techniques in evaluating lycopene contents of fruit. The novel techniques include both spectroscopic methods such as near infrared spectroscopy and Raman spectroscopy and spectral imaging approaches such as multispectral imaging, hyperspectral imaging and Raman imaging. The principles of these techniques are summarized, their detailed applications are discussed, and future trends are also presented. Both traditional and novel techniques highlighted in the current review can be used for assessing the distribution and concentration of lycopene in various fruit. Although novel spectroscopic and spectral imaging approaches may in the near future replace conventional methods, because conventional methods are typically often offline, destructive and time-consuming, which also require the use of chemicals.     

A multiresidue method for the determination of 107 pesticides in cabbage and radish using QuEChERS sample preparation method and gas chromatography mass spectrometry

A rapid, specific and sensitive multiresidue method based on the modified Quick Easy Cheap Effective Rugged and Safe (QuEChERS) sample preparation method and gas chromatography with the electron impact mass spectrometric detection in the selected ion monitoring mode (GC–MS-SIM) using one target and two qualifier ions for the routine analysis of 107 pesticides in cabbage and radish has been developed. The recoveries for all the pesticides studied were from 80% to 115% with relative standard deviation lower than 15% in the concentration range of 0.030–0.360 mg/kg. The limit of quantitation (LOQ) for most compounds met MRLs for pesticides in cabbage and radish in Korea. This method was successfully applied to analysis commercial cabbage and radish samples.     

A preliminary assessment of consumer’s exposure to organochlorine pesticides in fruits and vegetables and the potential health risk in Accra Metropolis,Ghana

Accra Metropolis is the major recipient of agricultural produce in Ghana, with almost the entire population depending on rural agricultural activities for subsistence. To increase agricultural produce, various forms of pesticides are normally used in fruits and vegetable farming. The consequence is that several cases of pesticide poisoning have been observed. In this preliminary study, a field survey was carried out to assess the knowledge, attitudes, and peoples’ perception concerning the use of pesticides by farmers in fruit production. The residual concentrations of selected pesticides in pawpaw, imported apples and tomato samples and the potential health risks associated with the exposure to these pesticides were also assessed. The field survey data indicated that more than 70% of the participants reported one or more poisoning upon fruits consumption resulting in pesticide-related illnesses. Pesticide residues in the various environmental samples were determined by gas chromatography with electron capture detector (GC-ECD). The results showed that, the levels of pesticide residues varied from <0.01 μg/g to as high as 0.11 μg/g depending on the pesticide monitored. The analysis of health risk estimates revealed heptachlor, heptachlor epoxide, endrin aldehyde, and endrin ketone levels exceeded the reference dose, suggesting a great potential for systemic toxicity in children considered the most vulnerable population subgroup. Lastly, the public is in the know of pesticide residues in fruits and calls for the curtailing of pesticide use on fruits and vegetable production via educational programmes for farmers on control and safer use of pesticides.     

Applications of Raman spectroscopic techniques for quality and safety evaluation of milk: A review of recent developments

Milk is a complete nutrient source for humans. The quality and safety of milk are critical for both producers and consumers, thereby the dairy industry requires rapid and nondestructive methods to ensure milk quality and safety. However, conventional methods are time-consuming and laborious, and require complicated preparation procedures. Therefore, the exploration of new milk analytical methods is essential. This current review introduces the principles of Raman spectroscopy and presents recent advances since 2012 of Raman spectroscopic techniques mainly involving surface-enhanced Raman spectroscopy (SERS), fourier-transform (FT) Raman spectroscopy, near-infrared (NIR) Raman spectroscopy, and micro-Raman spectroscopy for milk analysis including milk compositions, microorganisms and antibiotic residues in milk, as well as milk adulterants. Additionally, some challenges and future outlooks are proposed. The current review shows that Raman spectroscopic techniques have the promising potential for providing rapid and nondestructive detection of milk parameters. However, the application of Raman spectroscopy on milk analysis is not common yet since some limitations of Raman spectroscopy need to be overcome before making it a routine tool for the dairy industry.     

Ramie fibre: part I. Chemical composition and chemical properties. A critical review of recent developments

The monograph deals with a critical review of the recent research work and development on ramie, a long vegetable bast fibre. The review is divided into two parts. Part I discusses the progress of recent work on ramie, chemical components like fibre degumming, its effects on fibre composition, chemical constituents, i.e. hemicellulose, cellulose, non-cellulosic and mineral matters. Besides various chemical properties of native and modified fibres such as accessibility, infrared, cellulose I-V, DP, grafting, cross linking and resin finishing and dyeing etc. are dealt with.     

Development and validation of a probabilistic second-order exposure assessment model for Escherichia coli O157:H7 contamination of beef trimmings from Irish meat plants

A second-order quantitative Monte Carlo simulation model was developed for Escherichia coli O157:H7 contamination of beef trimmings in Irish abattoirs. The assessment considers initial contamination levels, cross-contamination and decontamination events during the cattle slaughter process. The mean simulated prevalence of E. coli O157:H7 on trimmings was 2.36% and the mean simulated counts of E. coli O157:H7 on contaminated trimmings was -2.69log(10)CFU/g. A parallel validation survey provided some confidence in the model predictions. An uncertainty analysis indicated that microbial test sensitivity is a significant factor contributing to model uncertainty and requires further investigation while also indicating that risk reduction measures should be directed towards reducing the hide to carcass transfer (correlation coefficient 0.25) during dehiding and reducing the initial prevalence and counts on bovine hides (correlation coefficients 0.19 and 0.16, respectively). A characterisation of uncertainty and variability indicating that further research is required to reduce parameter uncertainty and to achieve better understanding of microbial transfer in meat plants. The model developed in this study highlights the need for further development of quantitative risk assessments in the food industry.     

Bacterial biofilms in food processing environments: a review of recent developments in chemical and biological control

Biofilms are immobile communities of micro‐organisms attached to any surface, such as stainless steel or a food matrix surface or on packaging material. They may be composed of a single species, but more generally, in the natural environment, they consist of mixed species together with an extracellular matrix. Biofilms provide a common mechanism of persistence for a number of bacterial species especially in food processing environments, and therefore, prevention of biofilm formation and the removal of preformed biofilms are an important issue for the food industry. This article reviews the current understanding on the formation of biofilms and recent developments in biological and chemical methods for prevention and removal.     

Quality analysis,classification, and authentication of liquid foods by near-infrared spectroscopy: A review of recent research developments

Nowadays, near-infrared spectroscopy (NIR) has become one of the most efficient and advanced techniques for analysis of food products. Many relevant researches have been conducted in this regard. However, no reviews about the applications of NIR for liquid food analysis are reported. Therefore, this review summarizes the recent research developments of NIR technology in the field of liquid foods, focusing on the detection of quality attributes of various liquid foods, including alcoholic beverages (red wines, rice wines, and beer), nonalcoholic beverages (juice, fruit vinegars, coffee beverages, and cola beverages), dairy products (milk and yogurt), and oils (vegetable, camellia, peanut, and virgin olive oils and frying oil). In addition, the classification and authentication detection of adulteration are also covered. It is hoped that the current paper can serve as a reference source for the future liquid food analysis by NIR techniques.     

Microbial modulation of aromatic esters in wine: Current knowledge and future prospects

This review focuses on the considerable amount of research directed at defining the accumulation of esters during fermentation and their contribution to aromas in foods and beverages. From this research it is clear that esters are extremely important for the aroma profile of fermented beverages and various dairy products. A large amount of this research is focused on wine and has yielded the genes involved in ester synthesis and hydrolysis in organisms such as Saccharomyces sp. It is also clear from recent research in both the fermented beverage and dairy context that lactic acid bacteria possess an extensive collection of ester synthesising and hydrolysing activities. This review describes the major esters reported in wine and the enzymes responsible for their hydrolysis and synthesis. Ester impact on wine aroma and formation during primary and malolactic fermentation is also evaluated. Finally the potential applications of current knowledge are outlined.     

Survey of pesticide residues in table grapes: Determination of processing factors, intake and risk assessment

The differences in residue pattern between Italy and South Africa, the main exporters of table grapes to the Danish market, were investigated. The results showed no major differences with respect to the number of samples with residues, with residues being found in 54-78% of the samples. Exceedances of the European Union maximum residue limit (MRL) were found in five samples from Italy. A number of samples were rinsed to study the possible reduction of residues. For copper, iprodione, procymidone and dithiocarbamates a significant effect of rinsing was found (20-49% reduction of residues). However, no significant effect was found for organophosphorus pesticides and pyrethroids, whereas the number of samples with residues of benzilates, phenylamids and triazoles was insufficient to demonstrate any significant effects. An intake calculation showed that the average intake from Italian grapes was 3.9 µg day^-1 for pesticides and 21 µg day^-1 for copper. Correspondingly, the intakes from South African grapes were 2.6 and 5.7 µg day^-1, respectively. When the total exposure of pesticides from grapes were related to acceptable daily intake, expressed as the sum of Hazard Quotients, the exposure were approximately 0.5% for Italian samples and 1% for South African samples.