Terminal residue and dietary intake risk assessment of prothioconazole-desthio and fluoxastrobin in wheat field ecosystem

BACKGROUND

Wheat is one of the most important cereal crops worldwide, and use of fungicides is an essential part of wheat production. Both prothioconazole and fluoxastrobin give excellent control of important seed and soilborne pathogens. The combination of these two fungicides shows a complementary mode of action and has a wide usage around the world. But the residue levels of these fungicides in the wheat matrix are still unknown.

RESULTS

In the current study, a simple, low-cost and highly sensitive method using modified QuECHERS procedure combined with high-performance liquid chromatography-tandem mass spectrometry was developed to simultaneously quantify E- and Z-fluoxastrobin and the main metabolite prothioconazole-desthio of prothioconazole in the wheat matrix. The recoveries of prothioconazole-desthio, E-fluoxastrobin and Z-fluoxastrobin ranged from 84% to 101%, with relative standard deviation of less than 13.2%. The terminal residues of prothioconazole-desthio and E- and Z-fluoxastrobin were studied in wheat grain and straw under field conditions. The results showed that the terminal residue of the target compounds ranged from <0.01 to 0.029 mg kg^-1 and <0.05 to 7.6 mg kg^-1 in wheat grain and straw (expressed as dry weight), respectively. The risk quotients of prothioconazole-desthio and fluoxastrobin were 0.2% and 3.2%.

CONCLUSIONS

The residue levels of the target analytes in wheat grain were lower than the maximum residue limits recommended by the Chinese Ministry of Agriculture. And the calculated risk quotient values were far below 100%, indicating a low dietary intake health risk to consumers. © 2021 Society of Chemical Industry.

Validation of Multi-Residue Method for Quantification of Antibiotics and NSAIDs in Avian Scavengers by Using Small Amounts of Plasma in HPLC-MS-TOF

Pharmaceuticals are still considered emerging pollutants affecting both aquatic and terrestrial ecosystems. Scavenging bird species may be exposed to veterinary drugs when they feed on livestock carcasses provided at supplementary feeding stations, as these are often stocked with ailing and/or recently medicated animals. Because those animals may be a source of several different pharmaceutical compounds, analytical methods to evaluate residue levels and exposure potential should enable detection and quantification of as many different compounds as possible, preferably from small sample volumes. Four different extraction methods were tested to conduct HPLC-MS-TOF analysis of some of the most common veterinary drugs used in livestock in Spain. The method deemed most viable was a simple extraction, using methanol and 100 µL of plasma, that allowed quantification of seven antibiotics (tetracycline, oxytetracycline, ciprofloxacin, enrofloxacin, nalidixic acid, trimethoprim, sulfadiazine) and five nonsteroidal anti-inflammatory drugs (NSAIDs) (meloxicam, flunixin, carprofen, tolfenamic acid, phenylbutazone). The method was then applied to analysis of 29 Eurasian griffon vulture (Gyps fulvus) nestling samples, wherein enrofloxacin and tolfenamic acid were most commonly detected (69% and 20%, respectively). To our knowledge, this is the first study including NSAIDs in the exposure assessment of different classes of veterinary pharmaceuticals in live avian scavengers.

Effects of five sulphonamides on duckweed (Lemna minor) after prolonged exposure time and their dependency on photoradiation

Sulphonamides (SAs) are one of the most commonly used veterinary drugs and therefore their residues are regularly found in the environment. So far scientific attention has mostly been paid to the evaluation of their acute ecotoxicological effects with data on long-term effects for non-target organisms still largely missing. Therefore, the main aim of this study was to evaluate the potential toxicities of five sulphonamides to duckweed (Lemna minor) after prolonged exposure time (14days). To elucidate whether their phytotoxic effects result from potential photodegradation products, the toxicity of standard solutions of selected sulphonamides was also investigated in a standard 7-day test but after irradiation (by keeping them under the test conditions) for the selected time (after 7 and 14days). The ecotoxicological tests were accompanied by chemical analyses to be able to link the observed effects to the concentrations and nature of the exposed compounds. The results showed a shift in the toxicity of SAs: a strong decrease in toxicity for the two most toxic sulphonamides (sulphamethoxazole and sulphadimethoxine) and a slight increase in toxicity for three other SAs (sulphadimidine, sulphathiazole, sulphamerazine) in the prolonged test. However, a decrease in the toxicity and concentration of all the SAs was observed when stock solutions were irradiated prior to the toxicity experiment, which suggests that the observed effects towards L. minor of five SAs in the prolonged test cannot be directly associated with the degradation of these compounds under the test conditions but with their different mode of toxic action towards these organisms.

Effect of enrofloxacin on the proteome of earthworms

The environmental and human health risks of veterinary drugs are becoming public health issues. Enrofloxacin (EF) is an extensively used animal-specific antibacterial agent that leaves drug residues in the environment. This study investigated the proteomic response of the earthworm Eisenia fetida to EF exposure. Earthworms were exposed to EF in soil at 1-500mg·kg^-1, and samples were collected at intervals during a 28 day period. The extracted proteins were separated by two dimensional electrophoresis to detect differentially expressed proteins (DEPs) in EF-exposed earthworms. In total, 35 unique DEPs were found. These proteins were subjected to MALDI-TOF/TOF-MS analysis and identified through comparison of their mass spectra with those in protein databases. The DEPs were grouped on the basis of their function, into metabolism, stress-related, transport, transcription, and predicted/hypothetical protein categories. Knowledge of proteins that are induced or repressed by EF in earthworms could provide insight into mechanisms of sub-clinical physiological effects of xenobiotic residues in the environment, and may also help understand synergy between pollutants. As several DEPs in E. fetida showed similarity to human protein sequences, E. fetida has potential as an indicator species to assess the environmental and biological risks of drug residues.

Impacts of feeding preweaned calves milk containing drug residues on the functional profile of the fecal microbiota

Feeding drug residue-containing milk to calves is common worldwide and no information is currently available on the impact on the functional profile of the fecal microbiota. Our objective was to characterize the functional profile of the fecal microbiota of preweaned dairy calves fed raw milk with residual concentrations of antimicrobials commonly found in waste milk from birth to weaning. Calves were assigned to a controlled feeding trial being fed milk with no drug residues or milk with antibiotic residues. Fecal samples collected from each calf once a week starting at birth, prior to the first feeding in the trial, until 6 weeks of age. Antibiotic residues resulted in a significant difference in relative abundance of microbial cell functions, especially with genes linked with stress response, regulation and cell signaling, and nitrogen metabolism. These changes could directly impacts selection and dissemination of virulence and antimicrobial. Our data also identified a strong association between age in weeks and abundance of Resistance to Antibiotics and Toxic Compounds. Findings from this study support the hypothesis that drug residues, even at very low concentrations, impact the gut microbiota of calves and result in changes in the functional profile of microbial populations.

The importance of indicators in monitoring water quality according to European directives

Directive 2000/60/EC and subsequent legislation provide a list of priority substances to be measured and monitored in EU water bodies and require the adoption of analytical methods that ensure comparability of the data collected in all Member States. These regulations and standards have gradually improved water quality in the EU. However, new drugs, whose effects on ecosystems and health are still to be determined, are detected with growing frequency. The Member States are now called upon to characterize and monitor these pollutants in view of their possible inclusion in the priority substance list.

Pollution as a risk factor for the development of melasma and other skin disorders of facial hyperpigmentation ‑ is there a case to be made?

Worldwide air pollution is a major health concern. There is accumulating scientific evidence that air pollution plays an important role in extrinsic aging. This article invites the reader to consider pollution as a possible emerging etiologic agent for the development of melasma. Pollution may be a risk factor for melasma and other facial pigmentary dyschromias. Air pollution in the form of airborne particulate matter (PM) and Polycyclic aromatic hydrocarbons (PAHs) enter the skin via nanoparticles and generate quinones, which are redox-cycling chemicals that produce reactive oxygen species (ROS). The PM increases the amount of ROS that triggers the increase of metalloproteinases that leads to extrinsic aging, which includes skin pigmentation. The incidence of disorders of facial hyperpigmentation specifically, melasma, is increased in persons of skin type III-VI living in India and South East Asia. Interestingly, these are also geographic regions with very heavy pollution. India, South East Asia, China, and United States lead the world in air pollution.

[The presence of medications in the water cycle]

Medications and radiographic contrast dyes are sometimes detected in surface waters, ground water and drinking water; these have proven detrimental effects on organisms living in such waters The concentration of medications found in drinking water is at least a thousand times below their minimum therapeutic dosages. In humans, the long-term effects of daily exposure to low dosages of medications and 'mixture toxicity' is not known; based on the concentrations and substance toxicity, it is presumed that the risk is nil.. Physicians can play their part in controlling the problem of medications becoming part of the water cycle by taking this into account when prescribing medications. Users can make a difference by handling their medications with care and by returning all unused portions to the pharmacy. The pharmaceutical industry can also do its part by taking degradability, options for removal and the environmental effects of medications into account during their stages of development.

Patents for ELISA tests to detect antibiotic residues in foods of animal origin

The use of antibiotics in the European Union was banned since the 1(st) of January 2006. At present, and even though such ban, residues of drugs used in animal therapy or, illegally, as growth promoters might be found in food. Such residues may cause adverse health effects on consumers like allergic reactions in sensitive individuals develop transmissible antimicrobial resistance in food microflora, and have technological implications in the manufacture of fermented products. This is the reason why to check food for the presence of antibiotics residues is still necessary. ELISA test constitutes an attractive screening technique due to its simplicity, large number of samples per kit and possibility of automation. The aim of this manuscript is to provide a review of the numerous patents and applications for the analysis of antibiotic residues in foods.

Oseltamivir carboxylate, the active metabolite of oseltamivir phosphate (Tamiflu), detected in sewage discharge and river water in Japan

BACKGROUND

Oseltamivir phosphate (OP; Tamiflu) is a prodrug of the anti-influenza neuraminidase inhibitor oseltamivir carboxylate (OC) and has been developed for the treatment and prevention of both A and B strains of influenza. The recent increase in OP resistance in influenza A virus (H1N1; commonly called "swine flu") has raised questions about the widespread use of Tamiflu in seasonal epidemics and the potential ecotoxicologic risk associated with its use in the event of a pandemic.

OBJECTIVES

The objectives of this study were to develop an analytical method for quantitative determination of OC in sewage treatment plant (STP) effluent and receiving river water, and to investigate the occurrence of OC in STP effluent and river water in Japan during a seasonal flu outbreak.

METHODS

We developed an analytical method based on solid-phase extraction followed by liquid chromatography-tandem mass spectrometry. Using this method, we analyzed samples from three sampling campaigns conducted during the 2008-2009 flu season in Kyoto City, Japan.

RESULTS

The highest concentration of OC detected in STP discharge was 293.3 ng/L from a conventional activated-sludge-based STP; however, we detected only 37.9 ng/L from an advanced STP with ozonation as a tertiary treatment. In the receiving river water samples, we detected 6.6-190.2 ng/L OC, during the peak of the flu season.

CONCLUSION

OC is present in STP effluent and river water only during the flu season. Ozonation as tertiary treatment in STP will substantially reduce the OC load in STP effluent during an influenza epidemic or pandemic.

Microbial pollution in wildlife: Linking agricultural manuring and bacterial antibiotic resistance in red-billed choughs

The spread of pathogens in the environment due to human activities (pathogen pollution) may be involved in the emergence of many diseases in humans, livestock and wildlife. When manure from medicated livestock and urban effluents is spread onto agricultural land, both residues of antibiotics and bacteria carrying antibiotic resistance may be introduced into the environment. The transmission of bacterial resistance from livestock and humans to wildlife remains poorly understood even while wild animals may act as reservoirs of resistance that may be amplified and spread in the environment. We determined bacterial resistance to antibiotics in wildlife using the red-billed chough Pyrrhocorax pyrrhocorax as a potential bioindicator of soil health, and evaluated the role of agricultural manuring with waste of different origins in the acquisition and characteristics of such resistance. Agricultural manure was found to harbor high levels of bacterial resistance to multiple antibiotics. Choughs from areas where manure landspreading is a common agricultural practice harbor a high bacterial resistance to multiple antibiotics, resembling the resistance profile found in the waste (pig slurry and sewage sludge) used in each area. The transfer of bacterial resistance to wildlife should be considered as an important risk for environmental health when agricultural manuring involves fecal material containing multiresistant enteric bacteria including pathogens from livestock operations and urban areas. The assessment of bacterial resistance in wild animals may be valuable for the monitoring of environmental health and for the management of emergent infectious diseases influenced by the impact of different human activities in the environment.

Evaluation of certain veterinary drug residues in food

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of residues of certain veterinary drugs in food and to recommend maximum levels for such residues in food. The first part of the report considers general principles regarding the evaluation of veterinary drugs within the terms of reference of the Joint FAO/WHO Expert Committee on Food Additives (JECFA), including a hypothesis-driven decision tree approach for the safety evaluation of residues of veterinary drugs; comments on the Committee for Veterinary Products for Medicinal Use reflection paper on the new approach developed by JECFA for exposure and maximum residue limit (MRL) assessment of residues; residues of veterinary drugs in honey and possible approaches to derive MRLs for this commodity; comments on a paper entitled "Risk-assessment policies: Differences among jurisdictions"; and the use of no-observed-effect level (NOEL) and no-observed-adverse-effect level (NOAEL) in JECFA assessments. Summaries follow of the Committee's evaluations of toxicological and residue data on a variety of veterinary drugs: three antimicrobial agents (avilamycin, tilmicosin, tylosin), one anthelminthic (triclabendazole), one production aid (melengestrol acetate), two antimicrobial agents and production aids (monensin and narasin), a glucocarticosteroid (dexamethasone) and an antimicrobial agent and contaminant (malachite green). Annexed to the report is a summary of the Committee's recommendations on these drugs, including acceptable daily intakes (ADIs) and proposed MRLs.

A survey of antimicrobial use during bovine abdominal surgery by western Canadian veterinarians

Members of the Western Canadian Association of Bovine Practitioners were surveyed regarding their use of antimicrobials in bovine abdominal surgery. Perioperative antimicrobials were used in 100% of abdominal surgeries by 96 of 98 respondents. Although postoperative administration was the most common perioperative period for antimicrobial use, intraoperative intraperitoneal use was reported by more than half of the veterinarians surveyed. Procaine penicillin G and oxytetracycline were the most commonly administered perioperative antimicrobials.

Antibiotics threaten wildlife: circulating quinolone residues and disease in Avian scavengers

Antibiotic residues that may be present in carcasses of medicated livestock could pass to and greatly reduce scavenger wildlife populations. We surveyed residues of the quinolones enrofloxacin and its metabolite ciprofloxacin and other antibiotics (amoxicillin and oxytetracycline) in nestling griffon Gyps fulvus, cinereous Aegypius monachus and Egyptian Neophron percnopterus vultures in central Spain. We found high concentrations of antibiotics in the plasma of many nestling cinereous (57%) and Egyptian (40%) vultures. Enrofloxacin and ciprofloxacin were also found in liver samples of all dead cinereous vultures. This is the first report of antibiotic residues in wildlife. We also provide evidence of a direct association between antibiotic residues, primarily quinolones, and severe disease due to bacterial and fungal pathogens. Our results indicate that, by damaging the liver and kidney and through the acquisition and proliferation of pathogens associated with the depletion of lymphoid organs, continuous exposure to antibiotics could increase mortality rates, at least in cinereous vultures. If antibiotics ingested with livestock carrion are clearly implicated in the decline of the vultures in central Spain then it should be considered a primary concern for conservation of their populations.

[Impact on human health of hormonal additives used in animal production]

The establishment of the impact of environmental compounds or additives with hormone-like activity on human health still requires further investigation, as well as a reexamination of biologic models and experimental methodology employed so far. In 1988, the FAO/WHO Expert Committee on Food Additives Joint with the Federal Drug Administration (FDA) considered that sexual hormone residues usually present in meat do not represent a risk for human consumption. Nevertheless, this resolution seems to be uncertain since the scientific elements employed for this statement may not be adequate. In this review the principal objections to the evidence used to establish the innocuousness of growth promoter hormones are considered.

Residues from veterinary medicinal products, growth promoters and performance enhancers in food-producing animals: a European Union perspective

The authors present an overview of the presence of residues from veterinary medicinal products, growth-promoting agents and performance enhancers in food-producing animals, as a result of administering these substances--legally or illegally--on farms. The current situation in the European Union (EU) is represented by an analysis of the 2004 results from the national residue monitoring plans of EU Member States. Aspects of ante-mortem and postmortem inspection are also considered, as well as the practical challenges facing veterinary inspectors attempting to uncover illegal uses and prevent public health risks. Substances which are considered illegal because their risks have not yet been assessed, such as those employed in minority species or for minor uses, are also discussed.

Food safety hazards that occur during the production stage: challenges for fish farming and the fishing industry

Seafood derived from wild fish as well as farmed fish has always been an important source of protein in the human diet. On a global scale, fish and fish products are the most important source of protein and it is estimated that more than 30% of fish for human consumption comes from aquaculture. The first part of this paper outlines the hazards and challenges associated with handling fish during farming and capture. The authors describe infectious agents that cause disease in fish as well as humans, zoonotic agents, intoxications due to bacteria and allergies caused by the consumption of fish. Although only a few infectious agents in fish are able to infect humans, some exceptions exist that may result in fatalities. However, the greatest risk to human health is due to the consumption of raw or insufficiently processed fish and fish products. The second part of the paper considers environmental contaminants in seafood that may pose a risk to human health, such as medicinal products and residues associated with aquaculture, persistent lipophilic organic compounds and metals (methyl-mercury, organotin). The authors include an updated overview of the various factors associated with farmed and captured fish that may cause risks to human health after consumption. Moreover, they discuss the challenges (in the widest sense) associated with handling fish during capture and farming, as well as those encountered during processing.

On-farm contamination of animals with chemical contaminants

Food products should not contain unsafe levels of chemical contaminants. However, it is not possible to monitor each and every one of the many thousands of chemicals that are used in our advanced societies. Chemical contaminants in foodstuffs of animal origin may be classified into three categories: natural contaminants (e.g. mycotoxins), environmental contaminants linked to industrialisation and/or urbanisation (e.g. dioxins and dioxin-like compounds) and authorised chemical products (e.g. residues of veterinary medical products). Chemical hazards may contaminate foodstuffs of animal origin all the way from farm to fork. Contamination may occur in any of the different production systems, and it is difficult to make comparisons between production systems (e.g. extensive versus intensive farming systems) with regard to food safety. Even when we take into account the latest analytical methods, which can detect ever-smaller quantities of residues, the relative importance of chemical contaminants seems to have declined during recent decades due to improvements in information and prevention. Nonetheless, individual incidents can never be ruled out and may have serious economic, health or social repercussions. Particular attention must be paid to chemical hazards, in order to reduce as much as possible the risks to livestock and to the consumer. Continued monitoring and periodic reassessment of risks posed by these contaminants (at the national level) are needed to detect or anticipate new problems, so that appropriate actions can be taken in the interest of public health. More attention should be paid to the production of detailed information, especially with regard to background data (e.g. the objectives of the monitoring, sampling methods, chemicals to be analysed, analytical methods, detection limits, raw data and specified units), in order to obtain a better basis for risk assessment. Such risk assessment provides control authorities with an effective tool for the exchange of information and measures to be taken to ensure food safety.

Heavy use of prophylactic antibiotics in aquaculture: a growing problem for human and animal health and for the environment

The accelerated growth of finfish aquaculture has resulted in a series of developments detrimental to the environment and human health. The latter is illustrated by the widespread and unrestricted use of prophylactic antibiotics in this industry, especially in developing countries, to forestall bacterial infections resulting from sanitary shortcomings in fish rearing. The use of a wide variety of antibiotics in large amounts, including non-biodegradable antibiotics useful in human medicine, ensures that they remain in the aquatic environment, exerting their selective pressure for long periods of time. This process has resulted in the emergence of antibiotic-resistant bacteria in aquaculture environments, in the increase of antibiotic resistance in fish pathogens, in the transfer of these resistance determinants to bacteria of land animals and to human pathogens, and in alterations of the bacterial flora both in sediments and in the water column. The use of large amounts of antibiotics that have to be mixed with fish food also creates problems for industrial health and increases the opportunities for the presence of residual antibiotics in fish meat and fish products. Thus, it appears that global efforts are needed to promote more judicious use of prophylactic antibiotics in aquaculture as accumulating evidence indicates that unrestricted use is detrimental to fish, terrestrial animals, and human health and the environment.

Genotoxical, teratological and biochemical effects of anthelmintic drug oxfendazole Maximum Residue Limit (MRL) in male and female mice

Oxfendazole, methyl-5 (6)-phenylsulfinyl-2-benzimidazole carbamate, is a member of the benzimidazole family of anthelmintics. Anthelmintic benzimidazoles are widely used in meat producing animals (cattle, sheep and pigs) for control of endoparasites. The extensive use of veterinary drugs in food-producing animals can cause the presence of small quantities of the drug residues in food. Maximum residue limit or "MRL" means the maximum concentration of residue resulting from the use of a veterinary medicinal product which may be legally permitted recognized as acceptable in food. The FAO/WHO Expert Committee on Food Additives (1999) evaluations of toxicological and residue data, reported that oxfendazole (MRL) has toxicological hazards on human health. The toxicity of oxfendazole (MRL) was tested in male and female mice and their fetuses. Chromosomal aberrations, teratological examination and biochemical analysis were the parameters used in this study. The results show that oxfendazole MRL induced a mutagenic effect in all tested cell types. Also, oxfendazole exhibit embryotoxicity including teratogenicity. The biochemical results show that oxfendazole induced a disturbance in the different biochemical contents of all tested tissues. So, we must increase the attention paid to the potential risk of oxfendazole residues in human beings and should stress the need for careful control to ensure adherence to the prescribed withdrawal time of this drug.

Application of risk assessment and management principles to the extralabel use of drugs in food-producing animals

A risk assessment of the food safety implications of drugs used in food-producing animals is an essential component of the regulatory approval process for products containing these drugs. This ensures that there is negligible risk to human health if these drugs are used according to the instructions that appear on the approved label. A relative paucity of approved products for veterinary species; however, forces veterinarians worldwide to use drugs in an extralabel manner to treat disease and alleviate suffering in animals. In food-producing animals, this may result in residues that are potentially harmful to the human consumer. This review describes how risk assessment principles can be extended to evaluate the risks posed by different classes of extralabel drug use. Risk management practices in the United States and Europe are summarized and contrasted to illustrate the application of these principles.

Endectocide use in cattle and fecal residues: environmental effects in Canada

Endectocides, or macrocyclic lactones, are veterinary parasiticides used globally to control nematodes and arthropods affecting livestock. Cattle treated with these products fecally excrete residues that are toxic to dung-inhabiting insects, including species that accelerate dung degradation. Concerns have been raised that use of endectocides may reduce insect diversity and cause the accumulation of undegraded dung on pastures. This article synthesizes the results of studies performed to assess the nontarget effects of endectocide use in Canada. Residues reduce insect activity in dung of treated cattle for weeks to months after application. The duration of effect is influenced by several factors, including insect species and product. For example, in terms of toxicity, doramectin > ivermectin approximately equal to eprinomectin >> moxidectin. Reduced insect activity may retard dung degradation. Within the framework of regional conditions and management practices, endectocide use in Canada is unlikely to pose a significant widespread threat to the environment. Nevertheless, nontarget effects may be of concern to individual cow-calf operators, particularly those treating cattle in the spring. This synthesis, the first assessment of the nontarget effects of endectocide use in Canada, emphasizes the importance of presenting findings within an appropriate context.

Pain Detection and Amelioration in Animals on the Farm: Issues and Options

Pain in nonhuman animals is a difficult concept to identify and measure. This article briefly describes the consequences of pain in animals on the farm and explains the reasons for the minimal use of analgesics in farmed animals. Pain can have implications for both animal welfare and economics. The reasons for a low use of analgesics in farmed animals include the lack of recognition of animal pain owing to the apparent lack of anthropomorphically identifiable behavioral changes, concern over human food safety, and lack of research efforts to develop safe analgesics for farm use. Treatment cost relative to the benefits expected is another hindering factor. Interventions to minimize pain must begin with developing objective and practical measures for pain identification and measurement at the farm level. A suggested use of a combination of different behavioral and physiological indicators would help to identify pain in animals. To facilitate continued usage of the methodologies on the farm it also is necessary to evaluate the economic implication of the pain alleviation intervention.

High school dietary dairy intake and teenage acne

BACKGROUND

Previous studies suggest possible associations between Western diet and acne. We examined data from the Nurses Health Study II to retrospectively evaluate whether intakes of dairy foods during high school were associated with physician-diagnosed severe teenage acne.

METHODS

We studied 47,355 women who completed questionnaires on high school diet in 1998 and physician-diagnosed severe teenage acne in 1989. We estimated the prevalence ratios and 95% confidence intervals of acne history across categories of intakes.

RESULTS

After accounting for age, age at menarche, body mass index, and energy intake, the multivariate prevalence ratio (95% confidence intervals; P value for test of trend) of acne, comparing extreme categories of intake, were: 1.22 (1.03, 1.44; .002) for total milk; 1.12 (1.00, 1.25; .56) for whole milk; 1.16 (1.01, 1.34; .25) for low-fat milk; and 1.44 (1.21, 1.72; .003) for skim milk. Instant breakfast drink, sherbet, cottage cheese, and cream cheese were also positively associated with acne.

CONCLUSION

We found a positive association with acne for intake of total milk and skim milk. We hypothesize that the association with milk may be because of the presence of hormones and bioactive molecules in milk.

[A pilot study for the assessment of pharmaceuticals as water contaminants]

Pharmaceuticals and their metabolites can reach water bodies through sewage systems, industrial discharges, effluents from sewage treatment facilities, aquaculture and livestock farming. Pharmaceuticals include a huge number of substances which are very different as regards their chemical and physical properties and environmental behaviour, although they many have a potent biochemical activity. At present, pharmaceuticals can reach levels of ng-microg l(-1) and some are considered ubiquitous. Nevertheless, their presence in the aquatic environment and their impact on aquatic biota and on human health have not yet been adequately studied. There is some experimental evidence that pharmaceuticals may cause harmful effects such as morphological and metabolic alterations on aquatic species and induction of antibiotic-resistance in aquatic pathogenic bacteria. Risk assessment studies are in progress.

[Acrylamide, antiparasitic agents, dioxins and more: how dangerous are contaminants and residues in food?]

Within the European Union, food safety and consumer protection are topics of highest priority. The evaluation of the safety of contaminants and residues in food is usually based on the determination of the acceptable daily intake (ADI), which in turn is the basis for maximum residue levels (MRLs). As this procedure depends on animal testing, a safety factor of 100 is usually applied to provide a margin of safety. This paper discusses the occurrence of relevant contaminants (e.g. dioxins, acrylamide) and residues (e.g. antibiotics, antiparasitic agents) in food and provides a brief assessment of the risks resulting from the consumption of food containing these substances.

[The entry of bound residues of tetracyclines into the food chain--a contribution to hazard identification]

Actually, some 67% of therapeutical used antibiotics in livestock in the European Union are tetracyclines. Their use can result in unwanted residues in food of animal origin. Apart the risk of the possible development of resistances in enterobacteriaceae we have to keep in mind secondary circuits. This paper focuses on tetracycline residues in bones. Bones have been widely used as raw material for meat and bone meal and gelatine, and are also a frequent contamination of mechanical recovered meat. Bones contain tetracycline residues in concentrations up to 50 mg/kg. These bound tetracycline residues have ever been thought to be of no significance to health. Nevertheless, recent studies have shown that these tetracyclines could be released in vivo and re-obtain their bioavailability. Further, several toxic degradation products of tetracyclines could be formed during heating. Additionally, in acid solutions from the production of gelatine high tetracycline concentrations have been found. These solutions are processed to dicalciumphosphate, which is used as a feed supplement in animal husbandry and as fertilizer in agriculture.

Evaluation of certain veterinary drug residues in food

The first part of the report presents the views of the Committee on assessment of carcinogenic risk, quality of data, marker residues, and the Joint FAO/WHO Project to update the principles and methods for the risk assessment of chemicals in food. Summaries follow of the Committee's evaluations of toxicological and residue data on a variety of veterinary drugs: two antimicrobial agents (neomycin and flumequine), an antiprotozoal agent (imidocarb), three insecticides (deltamethrin, dicyclanil, and trichlorfon) and one production aid (carbadox). Annexed to the report is a summary of the Committee's recommendations on these drugs, including Acceptable Daily Intakes and Maximum Residue Limits. Corrigenda to WHO Technical Report Series 911: Evaluation of certain veterinary drug residues in food, 2002, are also included.

Evaluation of certain veterinary drug residues in food

This report presents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of residues of certain veterinary drugs in food and to recommend maximum levels for such residues in food. The first part of the report considers risk assessment principles and presents the views of the Committee on the FAO/WHO Project to update principles and methods for the risk assessment of chemicals in food. Summaries follow of the Committee's evaluations of toxicological and residue data on a variety of veterinary drugs: three anthelminthic agents (doramectin, ivermectin and tiabendazole), seven antimicrobial agents (cefuroxime, dihydrostreptomycin and streptomycin, lincomycin, neomycin, oxytetracycline and thiamphenicol), four insecticides (cyhalothrin, cypermethrin and alpha-cypermethrin, and phoxim) and one production aid (melengestrol acetate). Annexed to the report is a summary of the Committee's recommendations on these drugs, including Acceptable Daily Intakes and Maximum Residue Limits and further information required.

Medication of production animals--cure of malfunctioning animals or production systems?

Medication is used in all intensive animal productions. However, the increasing problems with resistant bacteria in all animal productions and in humans are supported by a number of reports. Special attention is given to the risk for transmitting food-borne (multi) resistant zoonotic agents to humans due to failure in antibiotic treatment resulting in lower cure rates or higher case fatality rates. The use of medication in humans per se is capable of selecting for resistance in human pathogens. Nevertheless, the amount of used medication/antimicrobials in treatment of Danish production animals goes far beyond the amount used for human consumption. The increase in consumption has not been followed by a similarly increased mortality, e.g. illustrated by the number of rendered animals, increased use of injection medicine for veterinary treatments of diseased animals, or increased number of remarks on the carcasses from the slaughterhouses. Medication in animal production is facing its limits and relevant economic alternatives have to be developed. The strategy for the future must concentrate on using medication only for clinically diseased animals and not as a strategic treatment of the whole herd in order to maximise growth and camouflage of suboptimal production systems and insufficient management.

Interspecies considerations in the evaluation of human food safety for veterinary drugs

Residues are composed of the parent drug and metabolites, and therefore interspecies comparisons must involve a consideration of comparative xenobiotic metabolism. The focus of this article will be the residue studies that are required to establish human food safety, and the interspecies pharmacokinetic differences and similarities that impact drug residues in animal- derived foods. To illustrate the factors that can complicate and assist these comparisons, 2 drugs will be examined in detail: ivermectin and fenbendazole. In addition, the activities of 2 US programs, the Food Animal Residue Avoidance Databank (FARAD) and the NRSP-7 (National Research Support Project Number 7) Minor Use Animal Drug Program will be presented, along with strategies that may be employed in the study of species differences.

Residual effect of antibabesial drugs on the live redwater blood vaccines

It has been demonstrated that the attenuated organisms used in the unfrozen South African Babesia bovis and B. bigemina (redwater) vaccines are susceptible for longer periods to the residual effect of the anti-babesial drugs diminazene and imidocarb dipropionate than the virulent field strains. Reports of vaccine failures in some animals vaccinated with the frozen South African redwater vaccines after prophylactic treatment with imidocarb dipropionate have led us to reinvestigate the validity of the recommended prescribed waiting periods. Results indicated that waiting periods before administration of the frozen B. bovis and B. bigemina vaccines in animals that have been treated with diminazene at 3.5 mg/kg live weight, compare favorably with results initially obtained for the unfrozen vaccines at 4 and 8 weeks, respectively. However, the inhibitory effect of imidocarb dipropionate at 3.0 mg/kg live weight on the infectivity of both frozen B. bovis and B. bigemina vaccines is longer than previously anticipated and necessitated changing the minimum waiting periods before administration of these vaccines from 8 to 12 weeks and 16 to 24 weeks, respectively.

Use of anthelmintics in herbivores and evaluation of risks for the non target fauna of pastures

The overall purpose ofthis paperwas to review the major and most recent literature relating the effects of anthelmintics on dung breeding invertebrates and dung degradation. Faecal residues or metabolites of drugs belonging to the benzimidazole and levamisole/morantel groups are relatively harmless to dung fauna, on the contrary to other anthelmintics such as coumaphos, dichlorvos, phenothiazine, piperazine, synthetic pyrethroids, and most macrocyclic lactones which have been shown to be highly toxic for dung beetles (abamectin, ivermectin, eprinomectin, doramectin), among which moxidectin was the less toxic for dung beetles. To date, the detrimental impact upon non-target organisms has been considered acceptable in eradicating the parasites because of their economic importance to commercial livestock production. The consequences of routine treatments are discussed with consideration of the long-term consequences for cow pat fauna and sustainable pastureland ecology.

Helminthic control on grazing ruminants and environmental risks in South America

The control of ruminant gastrointestinal nematodes and ectoparasites, one of the major production health problems, are heavily reliant on the systematic and sometimes abusive use of anthelmintic drugs. Endectocides are the most frequently used drugs, having high potency against arthropods and nematodes. Their dung pat residues enhance the risk of adverse effects on non-target invertebrates and on the general grazing cattle ecosystem. In this scenario, our objective is to review current knowledge of the agro-environmental and biodiversity impact and risks of endectocides in South America. The effects of faecal drug residues of ivermectin and doramectin on dung colonising invertebrates and dung degradation have been reported in studies carried out in the temperate centre of Argentina and in the subtropical region of Brazil. The results from Argentina showed a depression in invertebrate colonisation and degradation of dung recovered from endectocide treated cattle during the autumn. Comparisons have shown that ivermectin and doramectin have similar adverse effects. A decrease of Coleoptera larvae, Diptera larvae, Staphylinidae, Collembola, Acari and dung specific nematodes was noted in pats from both endectocides. The results from Brazil showed that dipterous larvae, Polyphaga coleopteran larvae and adults and mites were significantly reduced in the ivermectin treated group. The disturbances that macrocyclic lactones can produce on non-targeted invertebrates and on their associated participation in dung degradation and soil element recycling, are unpredictable and can negatively influence biodiversity and the agricultural ecosystem sustainability.

[Presence of residues and pollutants in human milk]

The contamination of human milk by xenobiotics is a common problem worldwide which is affected by the geographical, climate-related, cultural and socioeconomic variations in each individual location. Public health policies have dealt with this situation by means of ongoing monitoring and restrictive legislation in order to reduce the damaging effects on the populations and the environment, objectivatable data however being recorded particularly in the developing countries. Overall and individual aspects of waste and contaminating oganochlorines, organophosphorates, antibiotics, polychlorate biphenyls, dioxins and furans, their content values, toxic effects studies and the maximum limits permitted under international legislation are highlighted.