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PubMed2005

Effect of magnesium contamination in evacuated blood collection tubes on the prothrombin time test and ISI calibration using recombinant human thromboplastin and different types of coagulometer.

UNLABELLED: The purpose of the present study was to assess the effect of two types of evacuated blood collection tube on the prothrombin time and international sensitivity index (ISI) of Recombiplastin, a recombinant human thromboplastin. Vacutainer tubes were compared with Venoject II tubes. Magnesium contamination was detected in the sodium citrate solutions contained in the Vacutainer tubes with concentrations ranging from 1.1 to 1.5 mmol/l. In contrast, magnesium ions could not be detected in the Venoject II tubes. The prothrombin ratio was decreased by contamination with magnesium ions and, hence, the ISI was increased. The magnitude of the effect of magnesium contamination on the ISI was influenced by the type of coagulometer and increased in the order: ACL Advance (3%), ACL-300 (4%), Electra-1000 (6%). The ISI bias is transmitted to the international normalized ratio (INR). In the case of the Electra-1000, the INR bias would be approximately 6% at INR 3.0 if the two types of blood collection tubes would be used without distinction. In a secondary study, the effect of magnesium contamination on the prothrombin time was assessed with the current World Health Organization international reference preparation for recombinant human thromboplastin (rTF/95). Magnesium chloride added to patients' blood (0.2 mmol/l) induced 2.3% reduction of the INR determined with rTF/95 and the manual technique. CONCLUSION: The magnitude of the influence of blood collection tubes contaminated with magnesium on ISI and INR determined with recombinant human thromboplastin depends on the coagulometer.

Anticoagulants↗

PubMed1995

Anterior chamber contamination after uncomplicated phacoemulsification and intraocular lens implantation.

PURPOSE: To determine the frequency of anterior chamber contamination occurring during uncomplicated cataract surgery with intraocular lens implantation using phacoemulsification through a scleral tunnel incision. METHODS: In a prospective study, anterior chamber aspirates of one eye each of 103 consecutive ambulatory patients who underwent uncomplicated cataract surgery with lens implantation were cultured. The anterior chamber aspirate was withdrawn immediately upon the completion of surgery. Conjunctival cultures of the same eye were taken immediately before surgery, after the eye and periocular area had been prepared and draped. Multiple use topical medications used preoperatively on all patients were cultured at the end of the surgical day. RESULTS: Intraocular aspirates yielded positive cultures in five specimens (5%), four of which were identified as Staphylococcus epidermidis. Quantification disclosed colony counts ranging between 100 and 200 colony forming units per milliliter. Results of conjunctival cultures were positive in ten specimens (10%). Staphylococcus epidermidis was the most common isolate, identified in seven of the ten positive cultures. Positive intraocular and conjunctival culture results were not present concurrently in any patient. Microorganisms were recovered from the multiple use topical medications on nine of the 26 successive surgical days. Neisseria species was the most frequent isolate (7,44%), followed by S. epidermidis (5,31%). The frequency of contamination of the anterior chamber was independent of wound width (chi 2 = 0.869) and operative time (chi 2 = 4.77). CONCLUSION: Bacterial contamination of the anterior chamber was detected in five (5%) of the patients. This reduced incidence of contamination compared with that of previous studies may be related to the preoperative preparation, the surgical technique, or both. Contamination of the multiple use topical medications and bulbar conjunctiva define possible sources of pathogens that may enter the anterior chamber. The absence of any clinical ocular infection in all patients attests to the small inoculum sizes, as well as the ability of the anterior chamber to clear small bacterial loads.

Administration, Topical↗

PubMed1995

Evaluation of vitrectomy machines as a source of false-positive culture contamination in endophthalmitis.

PURPOSE: We sought to determine whether a venturi-aspiration vitrectomy machine could contaminate a vitrectomy culture. METHODS: Ninety vitrectomies were simulated in a hospital operating room and were cultured with standard techniques. An additional 90 control specimens were cultured in the exact same manner, but the vitrectomy machine was not used. Instead, the control specimens were placed directly into a sterile vitrectomy cassette. Contamination rates in the two groups were compared. RESULTS: Contamination occurred in four of 90 vitrectomy-simulation cultures and in three of 90 control cultures. This difference in contamination rate was not statistically significant. CONCLUSIONS: Although the result of a culture of the vitrectomy effluent can be false-positive, the source of contamination is not likely to be the vitrectomy machine.

Bacteria↗

PubMed2003

Bacterial contamination of Mediterranean coastal seawater as affected by riverine inputs: simulation approach applied to a shellfish breeding area (Thau lagoon, France).

Consequences of short-term changes in thermotolerant coliform loads on their spatio-temporal distribution in a Mediterranean lagoon with large-scale mollusk farming (Thau lagoon, France) were explored using a simulation approach. Simulations were based on bacterial transport and survival coupled models forced by the input of bacterial loads from the two main rivers (Vène and Pallas) that flow into the lagoon. Different flow types (reference, sudden and constant), bringing the same bacterial load, were considered and subsequent spatial and temporal bacterial contamination of lagoon surface water and shellfish was estimated. Simulation results showed that as long as loads were high, hydrodynamical processes governed the distribution of bacterial abundance in receiving areas. As soon as loads decreased or when time supply increased, biological die-off processes became dominant. Bacterial contamination of shellfish induced by the different flow types appeared to depend on the receiving area. In the case of Pallas River area, a sudden input of bacteria led to a high bacterial contamination of shellfish but only during a short period ( approximately 1 day). A constant input of the same amount of bacteria induced a lower but significant contamination during all the simulation period (10 days). On the contrary, bacterial inputs from the Vène River led to shellfish contamination only when bacteria were delivered through a flood event. Exposure time of bacteria to adverse environmental conditions appeared to be the main explanation to the above-mentioned differences. Consequences of our results in terms of environmental management strategy were discussed.

Animals↗

PubMed2003

Some aspects of toxic contaminants in herbal medicines.

A World Health Organisation survey indicated that about 70-80% of the world populations rely on non-conventional medicine mainly of herbal sources in their primary healthcare. In recent years, we have witnessed the increasing growth in popularity of over-the-counter (OTC) health foods, nutraceuticals, and medicinal products from plants or other natural sources in developed countries. This indirectly indicates that the public is not satisfied with their orthodox medical (OM) treatment. Such increase in popularity has also brought concerns and fears over the professionalism of practitioners, and quality, efficacy and safety of their treatment methods and products from herbal and natural sources available in the market. Over the past decade several news-catching episodes in developed communities indicated adverse effects, sometimes life threatening, allegedly arisen consequential to taking of OTC herbal products or traditional medicines from various ethnic groups. These OTC products may be contaminated with excessive or banned pesticides, microbial contaminants, heavy metals, chemical toxins, and for adulterated with orthodox drugs. Excessive or banned pesticides, heavy metals and microbial contaminants may be related to the source of these herbal materials, if they are grown under contaminated environment or during collection of these plant materials. Chemical toxins may come from unfavourable or wrong storage conditions or chemical treatment due to storage. The presence of orthodox drugs can be related to unprofessional practice of manufacturers. Some of these environment related factors can be controlled by implementing standard operating procedures (SOP) leading to Good Agricultural Practice (GAP), Good Laboratory Practice (GLP), Good Supply Practice (GSP) and Good Manufacturing Practice (GMP) for producing these medicinal products from herbal or natural sources. The public's belief that herbal and natural products are safer than synthetic medicines can only be ascertained by imposing regulatory standards on these products that should be manufactured using these Good Practices. Using Chinese medicines, as examples, this paper illustrate how advances in chemical and biomedical analysis would help to detect intentional and unintentional toxic contaminants in herbal substances. The paper also summarises how modernization and progress are being carried out to get the best out of Chinese medicines for public healthcare.

Consumer Product Safety↗

PubMed2002

Isotopic identification of the sources of lead contamination for white storks (Ciconia ciconia) in a marshland ecosystem (Doñana, S.W. Spain).

White storks (Ciconia ciconia) fed in contaminated waters resulting from the Aznacollar acid mining-sludge spillage into the R. Guadiamar, which feeds the eastern flank of the Guadalquivir marshes (Doñana), S.W. Spain. The sludge was rich in a range of toxic elements, and in organic pollutants such as the aromatic amines. Storks did not exhibit elevated metals in their blood immediately following the accident, but chick blood collected the year following the accident showed genotoxic damage compared to the controls. In this study lead isotope analysis was used to assess if the storks had ingested sludge-derived contaminants. The sludge lead isotope ratio was distinct from that of the Doñana sediments. The stork blood lead isotope ratios exactly matched that of the sludge. It was concluded that the storks had ingested sludge-derived contaminants. A detailed study of the lead contamination along the R. Guadiamar and the R. Guadalquivir (of which the Guadiamar is a tributary) was also conducted to place the white stork colony lead exposure in the context of the spatial contamination of the storks' habitat.

Animals↗

PubMed1997

Anaphylaxis after ingestion of wheat flour contaminated with mites.

BACKGROUND: Anaphylaxis after ingestion of flours contaminated with mites has been recently reported. OBJECTIVE: The study was designed to determine whether four-induced reactions in the absence of food sensitivity may result from mite contamination. METHODS: Patients with systemic reactions after ingestion of foods containing wheat flour and without food sensitivities were included in a prospective study. The flours were examined microscopically, and major Dermatophagoides allergens were quantified by monoclonal antibody techniques. Skin prick tests and IgE determinations to mites and flours were performed. Single-blind, placebo-controlled oral challenges were also performed. RESULTS: Sixteen patients were included in our protocol. They showed respiratory allergies to dust mites (100%) and intolerance to acetylsalicylic acid (87%). Microscopic examination of four flours implicated in allergic reactions revealed a high degree of mite contamination: Dermatophagoides farinae in one case and Thyreophagus entomophagus in three cases. Our patients' skin test and specific IgE responses to the flours implicated in the reactions were positive. A high level of Der 2 was found in the flour infested by D. farinae. Three of six food challenges with contaminated flours resulted in systemic reactions. Good tolerance to control flours was shown in our patients. CONCLUSION: Ingestion of foods contaminated with mites may induce systemic anaphylactic reactions in patients with respiratory allergy to mites.

Adolescent↗

PubMedDate not supplied

Humidification method that decreases condensate contamination in ventilator tubing.

OBJECTIVE: To demonstrate combining unheated bubble-through humidifier with a heat-moisture exchanger filter for the purpose of decreasing condensate contamination in mechanical ventilator tubing. DESIGN: Single-case, pretest and posttest. SETTING: University-affiliated and nonprofit hospital. PATIENT: A 32-year-old man with Pickwickian syndrome and pneumonia caused by Pseudomonas aeruginosa received mechanical ventilation for 14 days. METHODS: Ventilator tubing was cultured in two 24-hour trials, using a pretest and posttest design, to assess tubing bacterial contamination during use of 2 humidification methods. In the first trial, a traditional heated bubble-through humidifier (HBH) was used for 24 hours. Before the start of the second trial, the "wet" tubing and the heated bubble-through humidifier were removed and replaced with clean equipment through the use of aseptic technique. The bubble-through humidifier was placed on the "cold," or unheated mode, and a heat-moisture exchanger filter was attached to the Y-connector of the ventilator tubing. RESULTS: The heated bubble-through humidifier method revealed contamination of the ventilator tubing in 3 places with the patient's strain of P aeruginosa in addition to copious water condensate. The unheated bubble-through humidifier/heat moisture exchanger filter method demonstrated no bacterial contamination or condensate in the tubing. CONCLUSION: It can be inferred that the humidification method using the combination of an unheated bubble-through humidifier and a heat moisture exchanger filter has the potential benefit of preventing "reseeding" of the patient's airway with contaminated condensate.

Adult↗

PubMed2001

A comparative assessment of contaminants in fish from four resacas of the Texas, USA-Tamaulipas, Mexico border region.

A recent survey of contaminant information for the Lower Rio Grande Valley (LRGV), Texas, has shown that little is known about contaminants and their impacts on biota of resacas (oxbows) along the US-Mexico border. In 1996, fish were collected from four resacas in the Texas-Tamaulipas border region to assess contaminant loadings and their impacts on fish and birds. Tissue residue concentrations in fish were analyzed and also compared to two histopathological bioindicators of unhealthy environmental conditions. Of the organochlorine insecticides measured, DDE was the most common and was present at relatively high concentrations (10 microg/g w/w) at some sites. DDE concentrations were nearly 20 times greater in fish from resacas in Texas than from resacas in Tamaulipas, although the limited sample sizes obtained precluded statistical comparisons. DDE concentrations in fish from the two Texas resacas were also greater than those reported in fish from nearby areas during the 1980s and 1990s. Most trace element concentrations were similar among resacas from Texas and Tamaulipas. Arsenic, however, was two to six times greater in fish from a downtown resaca in Matamoros than in fish from other resacas in Tamaulipas and Texas. The bioindicators, pigment accumulation, and macrophage aggregates (MAs), in general, reflected the contamination indicated by the tissue residues for each site. Overall, it appears that some resacas of the US-Mexico border region are contaminant sinks and could pose potential health or reproductive problems for fish and wildlife, and humans that consume fish from those sites.

Animals↗

PubMed2002

Effects of slaughter processes on pig carcass contamination by verotoxin-producing Escherichia coli and E. coli O157:H7.

The aims of the present study were: (i) to evaluate verotoxin-producing Escherichia coli (VTEC) faecal carriage of slaughtered pigs; (ii) to determine the effects of three different pig slaughtering processes on pig carcass contamination by VTEC; (iii) to characterise the VTEC strains isolated from pig and pig slaughterhouses (virulence genes and serotype); and (iv) to compare the strains isolated in the same slaughterhouse in order to identify the routes of contamination inside the slaughterhouse. Pork carcasses from three French slaughterhouses were sampled at three steps of the slaughter process and different sites in each slaughterhouse were sampled at three different times in the work day. Faecal material from each sampled carcass, potable water and scalding water were also collected. Detection of stx genes was performed by polymerase chain reaction (PCR) on a total of 1227 samples. In addition, a second PCR specific for E. coli O157:H7 detection was carried out on the stx-positive samples. VTEC strains were recovered from positive samples by colony hybridisation or immunoconcentration, then serotyped, genetically characterised (eae, ehx, stx1, stx2, stx2c, uidA genes associated with virulence) and pulsotyped. No E. coli O157:H7 was isolated from the three uidA-positive samples. VTEC faecal carriage was 31%. Global carcass contamination decreased with slaughter process (from 46% to 15%), whereas environmental contamination increased (from 7% to 29%). No VTEC isolates harboured eae, ehx, and uidA genes. VTEC contamination routes were not clearly identified.

Abattoirs↗

PubMed2002

Effects of cutting process on pork meat contamination by verotoxin-producing Escherichia coli (VTEC) and E. coli O157:H7.

The aims of the present study were: (i) to evaluate verotoxin-producing Escherichia coli (VTEC) prevalence in pork cutting meat; (ii) to determine the effects of cutting process on pork meat contamination by VTEC; (iii) to characterise the VTEC strains isolated from pork and pork cutting plants (virulence genes and serotype); and (iv) to compare the strains isolated the same day in the same cutting plant in order to identify the routes of contamination inside the cutting plant. Pork carcasses from three French cutting plants were sampled before carcass cutting (carcass samples), after carcasses were divided into big portions (untrimmed cuts) and after preparation of primal cuts (rindless boneless cuts), and different environmental sites in each cutting plant were sampled at three different times in the work day. Potable water was also collected. PCR detection of stx genes was performed on a total of 2042 samples. In addition, a second PCR specific for E. coli O157:H7 detection was carried out on the stx-positive samples. VTEC strains were recovered from positive samples by colony hybridisation or immunoconcentration, then serotyped, genetically characterised (eae, ehx, stx1, stx2, stx2e, uidA and genes which are associated with virulence) and pulsotyped. No E. coli O157:H7 was detected. Meat contamination decreased from carcass (12%) and primary cuts (19%) to secondary cuts (5%), whereas environmental contamination increased after 2 h of activity (from 3% before the commencement of the work day to 25% and 20%, 2 and 6 h after commencement of cutting). No VTEC isolates harboured eae, ehx and uidA genes. VTEC contamination routes were not clearly identified.

Animals↗

PubMed2003

Contamination flows of Bacillus cereus and spore-forming aerobic bacteria in a cooked, pasteurized and chilled zucchini purée processing line.

A food processing plant producing pasteurized purées and its zucchini purée processing line were examined for contamination with aerobic and facultative anaerobic bacterial spores during a day's operation. Multiplication of spores was also monitored in the product stored under different conditions. High concentrations of Bacillus cereus spores were found in the soil in which the zucchinis were grown (4.6+/-0.3 log CFU/g), with a background spore population of 6.1+/-0.2 log CFU/g. In the processing plant, no B. cereus or psychrotrophic bacterial spores were detected on equipment. B. cereus and psychrotrophic bacterial spores were detected after enrichment in all samples of raw zucchinis, washed zucchinis, of two ingredients (starch and milk proteins) and in processed purée at each processing step. Steam cooking of raw zucchinis and pasteurization of purée in the final package significantly reduced spore numbers to 0.5+/-0.3 log CFU/g in the processed food. During storage, numbers of spore-forming bacteria increased up to 7.8+/-0.1 log CFU/g in purée after 5 days at 20-25 degrees C, 7.5+/-0.3 log CFU/g after 21 days at 10 degrees C and 3.8+/-1.1 log CFU/g after 21 days at 4 degrees C. B. cereus counts reached 6.4+/-0.5 log CFU/g at 20-25 degrees C, 4.6+/-1.9 log CFU/g at 10 degrees C, and remained below the detection threshold (1.7 log CFU/g) at 4 degrees C. Our findings indicate that raw vegetables and texturing agents such as milk proteins and starch, in spite of their low levels of contamination with bacterial spores and the heat treatments they undergo, may significantly contribute to the final contamination of cooked chilled foods. This contamination resulted in growth of B. cereus and psychrotrophic bacterial spores during storage of vegetable purée. Ways to eliminate such contamination in the processing line are discussed.

Bacillus cereus↗

PubMed1997

The potential for catheter microbial contamination from a needleless connector.

Needleless connectors have been widely introduced into clinical practice to allow the connection of syringes and luers to peripheral and central vascular catheters. The potential for microbial contamination of catheters via these devices is currently unclear. A recently introduced connector, the 'Connecta Clave', was assessed by various in-vitro methods. The 'Connecta Clave' is specifically devised to separate external components from the fluid pathway. The compression seals of 50 devices were contaminated with 1 x 10(4) cfu Staphylococcus epidermidis, disinfected with isopropanol, and fluid passed through. Only one device allowed organisms to pass through, despite this challenge, representing a contamination rate of 2%. In comparison, when 50 connectors were challenged with 20 cfu of S. epidermidis, no organisms passed through the device during use. In the clinical situation, after manipulation, < 16 cfu of skin organisms were found associated with the compression seal of the devices. It is, therefore, likely that the contamination rates in clinical practice will be extremely low. Three methods of disinfecting the compression seals and associated rims were also evaluated. A combination of alcohol chlorhexidine spray, followed by a 70% isopropanol swab, resulted in the most efficacious disinfection. The isopropanol swabs produced an adequate disinfection rate. The overall results suggest that by use of specially designed connectors, not only are needlestick injuries reduced, but the likelihood of microbial contamination of catheters via the internal route may also be diminished.

Catheters, Indwelling↗

PubMed1989

Peritonitis secondary to dialysis tubing contamination among patients undergoing continuous ambulatory peritoneal dialysis.

Patients were asked to report all dialysis system contaminations occurring from December 1985 through May 1988 to the home training facility. There were 74 instances of peritoneal dialysis system contamination, 20 of which resulted in peritonitis. Prophylactic antibiotics were used in 48 of 54 episodes not resulting in peritonitis. Three cultures yielded gram-positive organisms without clinical peritonitis becoming evident. Fourteen of the 20 episodes of peritonitis had received antibiotics prophylactically. System contaminations were classified into tears or holes of the catheter at the adapter on the Tenckhoff catheter or at the tubing connection to the dialysate bag and breaks of the connecting devices from either dialysis catheter to dialysis tubing or dialysis tubing to dialysate bag. System contaminations accounted for 20 of the 333 episodes of peritonitis that occurred during this time. Identifying system contamination is useful because prophylactic antibiotic therapy may prevent peritonitis.

Anti-Bacterial Agents↗

PubMed1995

The experimental study of microbial contamination of the space hardware.

The role of potential contaminants of design materials and products of space technology--aerobic and anaerobic prokaryotes (myxobacteria, eubacteria, corinebacteria, actinomyces), and eukaryotes (micromyces), psychrophilic, mesophilic and thermophilic forms, chemolythotrophic microorganisms is discussed in this paper. The methods of analysis of microbial contamination in the solution of problem of the planetary protection are considered. The necessity of the use of ultrasound at the evaluation of surface and subsurface contamination of specimens is demonstrated; methods of determination of buried contamination (with the use of organic solvents and mechanical pulverization) are discussed. The data on buried and subsurface contamination for some materials and electronic parts together with microflora resistivity to sterilizing treatment are given.

Bacteria↗

PubMed2001

Ineffectiveness of activated carbon in reducing the alteration of sphingolipid metabolism in rats exposed to fumonisin-contaminated diets.

Sphinganine/sphingosine (SA/SO) ratio, a biomarker of fumonisin exposure, has been measured in urine, kidney and liver of male Wistar rats exposed to fumonisin-contaminated diet with and without the addition of activated carbon (AC). The latter was previously shown to adsorb fumonisin B(1) in vitro. Rats were fed either control diet or fumonisin-contaminated diet (4 microg FB(1+)FB(2)/g) or fumonisin-contaminated diet mixed with 20 mg AC/g diet for 1 week. In rats fed fumonisin-contaminated diet, the SA concentration and SA/SO ratio increased significantly and reversibly in kidney, while urine and liver did not show a significant increase of SA/SO ratio. The addition of AC to the fumonisin-contaminated diet did not alter the change of SA/SO biomarker for fumonisin exposure. This provides indications that the use of AC to reduce the toxicity of fumonisins is unlikely to be effective in vivo.

Animal Feed↗

PubMed1994

Effect of ammoniation of aflatoxin B1-contaminated cottonseed feedstock on the aflatoxin M1 content of cows' milk and hepatocarcinogenicity in the trout bioassay.

The effectiveness of ammonia in inactivating aflatoxins in contaminated cottonseed was investigated. Two aflatoxin-contaminated cottonseed lots were treated separately using an atmospheric pressure, ambient temperature ammoniation procedure (APAT) or a high pressure, high temperature ammoniation procedure (HPHT), and incorporated into dairy cow rations. Isocalorific diets containing 25% defatted, dried milk from cows fed aflatoxin-contaminated cottonseed without or with APAT or HPHT treatment, or an aflatoxin-free human grade commercial milk powder, were then fed for 12 months to rainbow trout (Oncorhynchus mykiss). Aflatoxin M1 (AFM1) concentrations in milk powders without and with seed treatment were: APAT, 85 and < 0.05 microgram/kg; HPHT, 32 and < 0.05 microgram/kg. In the APAT experiment, trout consuming the diet containing milk from cows fed the aflatoxin-contaminated cottonseed had a 42% incidence of hepatic tumours; APAT cottonseed treatment reduced this to 2.5%. Positive controls were included to demonstrate trout responsiveness. AFB1 fed continuously for 12 months at 4 micrograms/kg resulted in a 34% tumour incidence, whereas positive controls fed 20 micrograms AFB1/kg, 80 micrograms AFM1/kg, or 800 micrograms AFM1/kg for 2 wk and killed 9 months later had a 37, 5.7 and 50% incidence of tumours, respectively. These data demonstrate that APAT ammonia treatment of aflatoxin-contaminated dairy cattle cottonseed feedstock abolished the detectable transfer of AFM1 or AFB1 into milk powder, and greatly reduced the carcinogenic risk posed by any carry-over of aflatoxins or their derivatives into milk. In addition, the results confirm AFM1 to be a lower level hepatocarcinogen in comparison with AFB1 in the trout carcinogenicity assay. In the separate HPHT experiment, no tumours were observed in the livers of trout fed diets containing milk from either the ammonia-treated or untreated source, or the control diet containing 8 micrograms AFM1/kg. Positive controls fed 64 micrograms AFB1/kg for 2 wk exhibited a 29% tumour incidence 12 months later. Thus in this experiment, neither AFM1 at 8 micrograms/kg nor any HPHT-derived aflatoxin derivatives that might have been carried over into milk, represented a detectably carcinogenic hazard to trout.

Aflatoxin B1↗

PubMed2003

Exposure assessment of environmental organic chemicals at contaminated sites: a multicompartment modelling approach.

For the prevention of future damages from chemicals at large contaminated sites, all transfer pathways leading to the exposure of man and vulnerable ecosystems have to be taken into account. For organic contaminants, the uptake into vegetation is the major entry route for the transfer into the food chains. Lipophilic substances are taken up by roots but are not translocated with the transpiration stream. Atmospheric background concentrations have a significant impact on foliage contamination due to the effective gaseous and particle deposition. Vegetables can also be contaminated after irrigation with contaminated water supplied by groundwater wells. By means of a multicompartment model, the various uptake processes into roots and foliage as well as the transformation and translocation processes are described and the concentration pattern resulting from daily irrigation with methyl-t-butyl ether in the edible parts is simulated. The results demonstrate the advantage of a dynamic multicompartment model over the static environmental quality standard approach in terms of derivation of possible exposure reduction measures for organic chemicals.

Food Contamination↗