Alternative Decontamination Research Articles

Design, economic evaluation and optimization of enzymatic membrane reactors for antibiotics degradation in wastewaters

A new technology based on laccase immobilized over ceramic membranes was formerly developed for the degradation of antibiotics from wastewaters. This work has been pointed to the determination of the economic aspects of this new enzymatic decontamination technology. These calculations have been based on previous modeling and simulations of real scale processes for tetracycline degradation in municipal, hospital and industrial WWTP effluents. A mathematical cost estimation model, originally developed for petrochemical wastewater treatment by ceramic membranes, has been adapted for the proposed enzymatic technology and applied to the subsequent economic viability analysis of the different designed processes in order to determine the competitiveness of this new technology compared to alternative decontamination technologies. Finally, some aspects where the new investigation efforts should be focused on to improve the process competitiveness and overcome the identified economic drawbacks have been proposed. Multi-objective optimization tools were employed to determine the magnitude of the required improvements in three main reactor characteristics: enzymatic kinetics, reactor effective lifetime, and membrane conditioning or regeneration costs. Under these improved conditions, the technology could be considered as a competitive alternative with specific total costs around 1 €/m3.

Removal of Contaminant DNA by Combined UV-EMA Treatment Allows Low Copy Number Detection of Clinically Relevant Bacteria Using Pan-Bacterial Real-Time PCR.

BackgroundMore than two decades after its discovery, contaminant microbial DNA in PCR reagents continues to impact the sensitivity and integrity of broad-range PCR diagnostic techniques. This is particularly relevant to their use in the setting of human sepsis, where a successful diagnostic on blood samples needs to combine universal bacterial detection with sensitivity to 1-2 genome copies, because low levels of a broad range of bacteria are implicated.ResultsWe investigated the efficacy of ethidium monoazide (EMA) and propidium monoazide (PMA) treatment as emerging methods for the decontamination of PCR reagents. Both treatments were able to inactivate contaminating microbial DNA but only at concentrations that considerably affected assay sensitivity. Increasing amplicon length improved EMA/PMA decontamination efficiency but at the cost of assay sensitivity. The same was true for UV exposure as an alternative decontamination strategy, likely due to damage sustained by oligonucleotide primers which were a significant source of contamination. However, a simple combination strategy with UV-treated PCR reagents paired with EMA-treated primers produced an assay capable of two genome copy detection and a <5% contamination rate. This decontamination strategy could have important utility in developing improved pan-bacterial assays for rapid diagnosis of low pathogen burden conditions such as in the blood of patients with suspected blood stream infection.

Eyewear contamination levels in the operating room: Infection risk

We investigated eyewear contamination levels in the operating room to assess infection risk and inform protocol development. Microbial contamination after use was found in 37.7% of disposable and 94.9% of reusable eyewear pieces. After disinfection, 74.4% of reusable eyewear also cultured positive. Disposable eyewear may reduce intercase contamination risk. Reusable eyewear may carry ongoing bioburden and, thus, contribute to operating room environment risk. Eyewear with antimicrobial material or components could reduce risk. Alternative decontamination methods for reusable eyewear should be evaluated.

Dielectric Barrier Discharge Atmospheric Cold Plasma for Inactivation of Pseudomonas aeruginosa Biofilms

In recent years, atmospheric cold plasma (ACP) has been widely investigated for potential application as an alternative decontamination technology in biomedical and healthcare sectors. In this study, the antimicrobial efficacy of ACP against Pseudomonas aeruginosa biofilms was investigated. The 48-h biofilms were treated inside sealed polypropylene containers with a high-voltage dielectric barrier discharge (DBD) ACP (80 kVRMS) and subsequently stored for 24 h at room temperature. Treatment for 60 s by either the direct or indirect mode of ACP exposure (inside or outside plasma discharge, respectively) reduced bacterial populations by an average of 5.4 log cycles from an initial 6.6 log10 CFU/mL. Increasing the treatment time from 60 s to 120 s and 300 s reduced biofilms to undetectable levels. According to XTT assay (a metabolic activity assay), an extended treatment time of 300 s was necessary to reduce metabolic activity of cells in biofilms by an average of 70%. Further investigation of biofilm viability by confocal laser scan - ning microscopy (CLSM) and scanning electron microscopy (SEM) demonstrated that extended ACP treatment had a detrimental effect on the viability of P. aeruginosa through disintegration of both bacterial cells and the biofilm matrix. The results of this study demonstrate the potential of a novel, in-package, high-voltage ACP decontamination approach for the inactivation of bacterial biofilms.

Bioburden assessment and gamma radiation inactivation patterns in parchment documents

Parchment documents are part of our cultural heritage and, as historical artifacts that they are, should be preserved. The aim of this study was to validate an appropriate methodology to characterize the bioburden of parchment documents, and to assess the growth and gamma radiation inactivation patterns of the microbiota present in that material. Another goal was to estimate the minimum gamma radiation dose (Dmin) to be applied for the decontamination of parchment as an alternative treatment to the current toxic chemical and non-chemical decontamination methods. Two bioburden assessment methodologies were evaluated: the Swab Method (SM) and the Destructive Method (DM). The recovery efficiency of each method was estimated by artificial contamination, using a Cladosporium cladosporioides spore suspension. The parchment samples' microbiota was typified using morphological methods and the fungal isolates were identified by ITS-DNA sequencing. The inactivation pattern was assessed using the DM after exposure to different gamma radiation doses, and using C. cladosporioides as reference. Based on the applied methodology, parchment samples presented bioburden values lower than 5×103CFU/cm2 for total microbiota, and lower than 10CFU/cm2 for fungal propagules. The results suggest no evident inactivation trend for the natural parchment microbiota, especially regarding the fungal community. A minimum gamma radiation dose (Dmin) of 5kGy is proposed for the decontamination treatment of parchment. Determining the minimal decontamination dose in parchment is essential for a correct application of gamma radiation as an alternative decontamination treatment for this type of documents avoiding the toxicity and the degradation promoted by the traditional chemical and non-chemical treatments.

Microgram-Level Radiocarbon Determination of Carbonaceous Particles in Firn and Ice Samples: Pretreatment and OC/EC Separation

Carbonaceous particles that comprise organic carbon (OC) and elemental carbon (EC) are of increasing interest in climate research because of their influence on the radiation balance of the Earth. The radiocarbon determination of particulate OC and EC extracted from ice cores provides a powerful tool to reconstruct the long-term natural and anthropogenic emissions of carbonaceous particles. However, this 14C-based source apportionment method has not been applied for the firn section, which is the uppermost part of Alpine glaciers with a typical thickness of up to 50 m. In contrast to glacier ice, firn samples are more easily contaminated through drilling and handling operations. In this study, an alternative decontamination method for firn samples consisting of chiselling off the outer parts instead of rinsing them was developed and verified. The obtained procedural blank of 2.8 ± 0.8 μg C for OC is a factor of 2 higher compared to the rinsing method used for ice, but still relatively low compared to the typical OC concentration in firn samples from Alpine glaciers. The EC blank of 0.3 ± 0.1 μg C is similar for both methods. For separation of OC and EC for subsequent 14C analysis, a thermal-optical method instead of the purely thermal method was applied for the first time to firn and ice samples, resulting in a reduced uncertainty of both the mass and 14C determination. OC and EC concentrations as well as their corresponding fraction of modern for firn and ice samples from Fiescherhorn and Jungfraujoch agree well with published results, validating the new method.

Alternative Sanitizing Methods to Ensure Safety and Quality of Fresh-Cut Kiwifruit

The effect of different sanitizing methods as alternative decontamination treatments to chlorinated-water, on microbiological counts, packaging atmosphere composition, color and firmness of fresh-cut kiwifruit under refrigerated conditions was evaluated. The fruits were subjected, within minimal processing, to water, chlorinated water (150 ppm free chlorine), ozonated water (0.2 ppm), UV-C (1 kJ/m2) or heat-shock treatment (95C/30 s). Results showed that UV-C and heat-shock treatments were efficient with respect to microbial quality of fruits, by maintaining the microbial loads below the legal or recommended limits during 10-day storage. No significant (P < 0.05) reduction of the initial microbial flora was observed in kiwi slices treated with ozonated water and chlorine. UV-C treatment was also effective in reducing respiration rate of kiwifruit slices. No significant changes (P < 0.05) in color parameters (L*, c and h°) were observed in kiwi slices submitted to different sanitizing methods. UV-treated fruits showed a significant (P < 0.05) increase in firmness value. PRACTICAL APPLICATIONS In minimally processed vegetables, namely in sliced fruits, chlorine solutions have been widely used by the industry for sanitization purposes. However, reduced microbiological efficiency allied to the sensory alteration and eventual formation of carcinogenic chlorinated compounds pointed out the need for alternative decontamination methodologies. Also, the evermore conscious consumers are demanding minimization of the potentially negative impact of food processing on human health and the environment.

EVALUATION OF OZONATED WATER AS AN ALTERNATIVE TREATMENT TO CHLORINE IN FRESH-CUT 'ROCHA' PEAR PROCESSING

ISHS XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Postharvest Technology in the Global Market EVALUATION OF OZONATED WATER AS AN ALTERNATIVE TREATMENT TO CHLORINE IN FRESH-CUT 'ROCHA' PEAR PROCESSING

Decontamination of Prions by the Flowing Afterglow of a Reduced‐pressure N2O2 Cold‐plasma

AbstractTransmissible spongiform encephalopathies, also called prion diseases, represent a family of neurodegenerative disorders that affect various animal species. Since the infectious forms of prions are transmissible and highly resistant to chemical and physical decontamination methods routinely used in healthcare, they represent a challenge for science, medicine, and public health/food systems. Suitable decontamination procedures have been proposed, but they are generally incompatible with the materials from which medical devices are made. In this study, we evaluate a cold gaseous‐plasma treatment, based on the outflow from a N2O2 microwave discharge, as an alternative decontamination tool against both the non‐infectious (PrPC) and infectious (PrPSc) forms of prion proteins. The efficiency of the plasma treatment on these proteins is assessed using an in vitro assay as well as an in vivo bioassay. We showed by Enzyme‐Linked Immuno‐Sorbent Assay (ELISA) that the N2O2 discharge afterglow reduces the immunoreactivity of both non‐infectious recombinant and pathogenic prion proteins deposited on polystyrene substrates. Tests done in vivo demonstrate that exposure to the cold‐plasma flowing afterglow achieves significant decontamination of stainless steel sutures inoculated with infectious forms of prions to be implanted in mice.magnified image

Roles of hydroxyl radicals in electrolyzed oxidizing water (EOW) for the inactivation of Escherichia coli

The food industry has recognized electrolyzed oxidizing water (EOW) as a promising alternative decontamination technique. However, there is not a consensus about the sanitizing mechanism of EOW. In this study, we evaluated the disinfection efficacy of different types of EOW on Escherichia coli. Based on the hypothesis of hydroxyl radicals existing in EOW, in the present study, the hydroxyl radicals existed in slightly acidic electrolyzed water (SAEW) and acidic electrolyzed water (AEW) diluted to different levels were detected quantitatively. An ultraviolet (UV) spectrophotometer was used to scan EOW with different pH values. Accounting for the results of UV scanning to EOW with different pH value and the disinfection efficacy of different types of EOW, it can be concluded that considering the lower chlorine concentration of EOW compared with traditional chlorine disinfectants, the existing form of chlorine compounds rather than the hydroxyl radicals played important role in the disinfection efficacy of EOW.

Activated Charcoal Effectively Removes Inhaled Anesthetics from Modern Anesthesia Machines

If a malignant hyperthermia-susceptible patient is to receive an anesthetic, an anesthesia machine that has been used previously to deliver volatile anesthetics should be flushed with a high fresh gas flow. Conflicting results from previous studies recommend flush times that vary from 10 to 104 minutes. In a previously proposed alternative decontamination technique, other investigators placed an activated charcoal filter in the inspired limb of the breathing circuit. We placed activated charcoal filters on both the inspired and expired limbs of several contaminated anesthesia machines and measured the time needed to flush the machine so that the delivered concentrations of isoflurane, sevoflurane, and desflurane would be <5 parts per million (ppm). We next simulated the case for which malignant hyperthermia is diagnosed 90 minutes after induction of anesthesia and measured how well activated charcoal filters limit further exposure. Activated charcoal filters decrease the concentration of volatile anesthetic delivered by a contaminated machine to an acceptable level in <2 minutes. The concentrations remained well below 5 ppm for at least 60 minutes. When malignant hyperthermia is diagnosed after induction of anesthesia, we found that with charcoal filters in place, the current anesthesia machine may be used for at least 67 minutes before the inspired concentration exceeds 5 ppm. Activated charcoal filters provide an alternative approach to the 10 to 104 minutes of flushing that are normally required to prepare a machine that has been used previously to deliver a volatile anesthetic.

Identification and characterization of breakthrough contaminants associated with the conventional isolation of Mycobacterium tuberculosis

Breakthrough contamination of tuberculosis (TB) cultures is a problem in that it allows the overgrowth of another bacterium present in the sputum specimen, which can potentially mask the presence of Mycobacterium tuberculosis. The aim of this study was to isolate and characterize the bacterial organisms responsible for such overgrowth and contamination, and to examine their susceptibility to (i) various chemical selective decontamination steps and (ii) antibiotics in liquid culture media, in an attempt to develop a method to help alleviate contamination problems associated with the conventional isolation of M. tuberculosis from routine patient sputum specimens. Bacterial contaminants from 102 routine sputum cultures were identified molecularly by 16S rRNA gene PCR and direct sequencing from contaminated Löwenstein-Jensen (LJ) slopes and BacT/Alert liquid medium. It was found that the contaminants from LJ slopes belonged to 11 different genera and were composed largely of Gram-negative organisms (84.9 %; 45/53), whereas the liquid culture contaminants belonged to 13 different genera, with 37/66 isolates (56.1 %) being Gram-negative. Pseudomonas aeruginosa was the dominant contaminant in both media. The effect of six different selective decontamination protocols was examined. Four of the six methods were effective at eliminating all culturable organisms present; these were 5 % oxalic acid, 5 % oxalic acid/2 % NaOH, 5 % oxalic acid/4 % NaOH and 1 % chlorhexidine. NaOH at a concentration of 2 or 4 % was less effective as it was unable to eliminate all organisms of each species tested, with the exception of P. aeruginosa. In conclusion, breakthrough contamination of TB cultures is due to a diverse range of at least 17 different bacterial genera, with P. aeruginosa and Staphylococcus epidermidis accounting for the dominant contaminating flora. Employment of chemical decontaminating protocols solely involving NaOH may lead to higher rates of contamination. Where such contamination is encountered, TB laboratories should consider the reprocessing of such sputum samples with an alternative decontamination method such as 1 % chlorhexidine.

Decontamination of Raw Foods Using Ozone-Based Sanitization Techniques

Popular foods such as fresh produce and dry nuts are increasingly implicated in outbreaks of food-transmitted diseases. These products are not amenable to conventional processing technologies; therefore, many alternative decontamination methods are actively investigated. Ozone is a versatile sanitizer with promising applications in some high-risk foods. This antimicrobial agent is active against a broad spectrum of microorganisms, and it can be used effectively in its gaseous or aqueous state. The flexibility afforded by ozone use makes it a viable option for application on easy-to-damage products like fresh produce. If process parameters are adequately controlled, ozone treatment can enhance safety and increase shelf life without adversely affecting product quality. Despite these advantages, ozone may not be suitable for some applications, including treatment of liquid foods and products rich in unsaturated fats and soluble proteins. Ozone, as a powerful oxidizer, must be carefully controlled at all times, and equipment must be rigorously maintained to ensure safety of workers.

Pulsed UV light inactivation of Salmonella enteritidis on eggshells and its effects on egg quality.

The majority of Salmonella Enteritidis outbreaks have been related to the consumption of raw or undercooked eggs or egg-containing foods. Therefore, the U.S. Department of Agriculture mandates egg washing for all graded eggs by use of a detergent solution and sanitizer. These agencies and the egg industry have been investigating alternative decontamination techniques, which could better serve the public, minimize costs, and benefit both the public and the industry. Pulsed UV light is an emerging technology that is used to inactivate microorganisms quickly. In this study, the effectiveness of pulsed UV light was evaluated for the decontamination of eggshells. Eggs inoculated with Salmonella Enteritidis on the top surface at the equator were treated with pulsed UV light 1 to 30 s, at a distance of 9.5 and 14.5 cm from the UV lamp in a laboratory-scale, pulsed UV light chamber. Three eggs were used per treatment in each repetition, except for quality measurements, which involved six eggs per treatment in each repetition. A maximum log reduction of 5.3 CFU/cm2 was obtained after a 20-s treatment at 9.5 cm below the UV lamp at a total dose of 23.6+/-0.1 J/cm2, without any visual damage to the egg. After a 30-s treatment at 9.5 and 14.5 cm, the temperature of eggshell surfaces increased by 16.3 and 13.3 degrees C, respectively. Energy usage increased up to 35.3+/-0.1 and 24.8+/-0.1 J/cm2, after 30-s treatments at 9.5 and 14.5 cm, respectively. The effect of pulsed UV light treatments on egg quality was also evaluated. Pulsed UV-light treatments for 3, 10, and 20s at either 9.5 or 14.5 cm did not change the albumen height, eggshell strength, or cuticle presence significantly (P<0.05). This study demonstrated that pulsed UV light has potential to decontaminate eggshell surfaces.

University of North Carolina's Experience With State Medical Assistance Teams

Events in the last several years have shown a clear need for better preparation regarding disaster management. In an effort to improve this preparation, North Carolina implemented state medical assistant teams to provide alternative care facilities, decontamination facilities, and shelter assistance during times of disaster. This article explores these teams from the perspective of the University of North Carolina, which serves as a lead agency for one of these teams. Key components of the team, training provided, and lessons learned will be discussed.

Evaluation of a pre-cut heat treatment as an alternative to chlorine in minimally processed shredded carrot

Abstract The effect of a pre-cut heat treatment (100 °C/45 s) as an alternative decontamination treatment to chlorinated-water (200 ppm active chlorine/1 min, 5 °C) was evaluated in minimally processed carrot (shredded). The quality of shredded carrots was studied just after minimal processing and during storage at 5 °C (10 days) by evaluating microbial (total mesophilic aerobic, yeast and moulds and lactic acid bacteria counts), physical–chemical (soluble solids content, pH, titratable acidity, whiteness index), physiological (peroxidase activity and headspace analysis) and sensorial attributes (colour, fresh-like appearance, aroma and general acceptance). The relationships between sensory perception of undesired changes, microbial contamination threshold, physico-chemical and physiological indices were investigated and compared between heat-treated and control samples. The use of heat in pre-cut carrot proved to be more efficient than chlorinated-water concerning microbial control (threshold concentration of 7 Log10 cfu g− 1), providing an acceptable fresh-like quality product during 10 days of storage (5 °C), which corresponds to a 3-day shelf-life extension compared to control samples. Heat-treated shredded carrot showed lower respiratory and POD activities than chlorinated samples suggesting that the use of heat provides a metabolic activity lowering effect besides the microbial effect which could be important to shelf-life extension of the fresh-cut product. Industrial relevance In minimally processed vegetables, namely in shredded carrot, chlorine solutions have been widely used by the industry for sanitization purposes. However, reduced microbiological efficiency allied to sensorial changes and eventual formation of carcinogenic chlorinated compounds pointed out the need for alternative decontamination methodologies. Also, the evermore conscious consumers are demanding minimization of the potentially negative impact of food processing on human health and the environment. From the practical experience of a fresh-cut industry directly involved in the R&D research project which supported this study, the marketability of minimally processed shredded carrot is limited due to rapid microbial growth and colour loss (decrease of orange intensity and/or whitening of the shreds). As a result, a pilot-plant scale study was performed, evaluating quality attributes of shredded carrot processed according to a clean pre-cut alternative decontamination process.

Quality attributes of shredded carrot (Daucus carota L. cv. Nantes) as affected by alternative decontamination processes to chlorine

The effects of alternative decontamination processes to chlorine: ozonated-water (1 ppm/5 min), hot water (100 °C/45 s) and ultrasonication (45 kHz/1 min), applied pre- or post-cut in the technological diagram of minimal processing of carrots were tested. Ultrasonication in chlorinated-water and thermo-ultrasonication as combined processes applied just in pre-cut carrot were also tested. The initial microbial load reduction, soluble solids content, pH and sensorial attributes of shredded carrot just after processing were evaluated. Decontamination processes applied on pre-cut carrot provided maintenance of fresh-like sensorial quality, regardless the type of treatment, due to diminished leaching phenomena which is critical for shredded carrot. Chlorination, ozonization and ultrasonication achieved ca. 1 Log10 reduction of initial microbial load. No additional decontamination effect in combined processes was observed. The use of heat in pre-cut carrot proved to be the most efficient process regarding microbial reduction (3 Log10 units) providing, as well, an acceptable fresh-like quality product. The major constraint for marketability of minimally processed shredded carrot is its limited shelf-life due to rapid microbial growth and colour loss (decrease of orange intensity and/or whitening of the shreds). These questions arise from the practical experience of a fresh-cut industry directly involved in the R&D research project which supported this study. Chlorine solutions have been widely used to sanitize fruit and vegetables in the fresh-cut industry. However, reduced microbiological efficiency allied to the eventual formation of carcinogenic chlorinated compounds pointed out the need for alternative methodologies. The present work aimed the evaluation of clean alternative decontamination processes applied both to pre- and post-cut carrot for the production of shredded carrot, operating under conditions of industrial practice at pilot-plant scale.

The efficiency of magnetic-activated cell sorting and fluorescence-activated cell sorting in the decontamination of testicular cell suspensions in cancer patients

Before clinical application, the feasibility and safety of autologous testicular stem cell transplantation should be explored. Apart from limitations in their numbers, spermatogonial stem cells may also be contaminated by malignant cells. Therefore, both enrichment and decontamination before transplantation may be necessary. This study aimed at evaluating the decontaminating potential of magnetic-activated cell sorting (MACS) and/or fluorescence-activated cell sorting (FACS) for both murine and human testicular cell suspensions. In the mouse, the effectiveness of the transplantation technique after cell sorting was also assessed. Murine testicular cells were contaminated with 5% EL4 cells. Fresh and frozen-thawed suspensions were sorted using MACS (CD49f (+)) and FACS (CD49f(+), H-2Kb(-)) and evaluated by FACS, cell culture and transplantation into W/W(v) mice. Human testicular cells were contaminated with 5 or 0.05% CCRF-SB (SB) cells. Frozen-thawed suspensions were sorted using FACS (HLA class I(-)) and evaluated by FACS, cell culture and PCR for the B-cell receptor. In the mouse, the sorted fractions contained 0.39% H-2K(b)-positive and 76.55% CD49f-positive cells. After transplantation, 1 in 20 recipient mice developed a malignancy. In the human experiments, an average of 0.58% SB cells was detected after sorting. In only 1 of 11 samples, there were no SB cells observed. MACS and/or FACS are insufficient for completely depleting testicular tissue of malignant cells. Although more research on alternative decontamination techniques is necessary, developing a reliable method to screen a priori testicular tissue for malignant cells may be equally important.

Factors Limiting the Efficacy of Hydrogen Peroxide Washes for Decontamination of Apples Containing Escherichia coli

ABSTRACT:Factors limiting efficacy of H2O2 washes and alternative decontamination strategies were investigated with Golden Delicious apples, inoculated with nonpathogenic Escherichia coli. Post‐treatment rinsing decreased efficacy by eliminating residual H2O2. A 2‐stage wash incorporating a rinse to remove surfactant residues prior to H2O2 application was developed. Rapid attachment of E. coli to apples prevented effective removal by washing with water. Surviving E. coli following a 5% H2O2 wash were concentrated in stem and calyx areas. Survival was independent of the time interval between inoculation and washing. E. coli inoculation of punctured apple surfaces resulted in growth at 20 °C and greater survival after washing with 5% H2O2. Improved decontamination methods are needed.

Radiation processing of dry food ingredients - a review

Radiation decontamination of dry ingredients, herbs and enzyme preparations is a technically feasible, economically viable and safe physical process. The procedure is direct, simple, requires no additives, does not leave residues and is highly efficient. Its dose requirement is moderate. Radiation doses of 3 to 10 kGy proved to be sufficient to reduce the viable cell counts to a satisfactory level. Ionizing radiations do not cause any significant rise in temperature and the flavour, texture or other important technological or sensory properties of most ingredients are not influenced at radiation doses necessary for a satisfactory decontamination. The microflora surviving the cell-count reduction by irradiation is more sensitive to subsequent food processing treatments than the microflora of untreated ingredients. Recontamination can be prevented since the product can be irradiated in its final packaging. Irradiation can be carried out in commercial containers and it results in considerable savings of energy and labour as compared to alternative decontamination techniques. Radiation processing of dry ingredients is an emerging technology in several countries and more-and-more clearances on irradiated foods are issued or expected to be granted in the near future.