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PubMedDate not supplied

Influence of residential fungal contamination on peripheral blood lymphocyte populations in children.

Reported residential fungal contamination has been associated consistently with increased symptoms among occupants; however, an objective measure of a health effect is lacking, and a pathophysiologic mechanism has not been established. Our objective was to determine if exposure to indoor fungal contamination influenced T-cell differentiation. In this study, we contrasted lymphocyte populations, measured by flow cytometry, between a group of children who lived in homes with considerable fungal contamination (n = 39) and a group in less-contaminated homes (n = 20). Indicators of fungal biomass were viable fungi in house dust and air ergosterol in the child's bedroom. Living in a more-contaminated home versus a less-contaminated home was associated with a larger number of CD3+ T cells expressing CD45RO (1.5 x 10(9)/I versus 1.1 x 10(9)/I, respectively; p = .05, two-tailed t testing) and a reduced CD4/CD8 ratio (1.6 versus 1.8, respectively; p = .04). The differences persisted over a 12-mo period, and they were not explained by the child's age or total serum IgE, dust mite antigens, and the presence of furry or feathered pets or a humidifier. The results suggest that residential fungal contamination leads to chronic stimulation of children's lymphocytes.

Air Microbiology↗

PubMed2005

Risk factors associated with Salmonella enterica subsp. enterica contamination of chicken carcases in Senegal.

This study was to identify the risk factors for Salmonella spp. contamination of Senegalese chicken carcases during slaughtering. One hundred and twenty traditional slaughterhouses were studied from January 2000 to December 2002 in and around Dakar. A questionnaire was answered by the slaughterers, and samples of breast skin were taken to assess the Salmonella status of chicken carcases. Results showed that 43.3% of the batches were contaminated with Salmonella, indicating Salmonella Hadar and Salmonella Brancaster as the two main serovars. Salmonella contamination of the carcases after slaughtering was related to contamination of the live birds. Feed withdrawal before slaughtering and thorough cleaning and disinfection procedures decreased the risk of contamination. One individual worker for each slaughtering stage was also associated with a decreasing risk of contamination. Using scalding water for plucking the chicken carcases increased contamination risk. These results will help slaughters to produce safer products for local consumers.

Abattoirs↗

PubMed2005

Bacterial eggshell contamination in conventional cages, furnished cages and aviary housing systems for laying hens.

The influence of housing system on the initial bacterial contamination of the eggshell was studied. Two long-term experiments were performed. Bacterial eggshell contamination, as expressed by total count of aerobic and Gram-negative bacteria, was periodically analysed for eggs from a conventional cage, a furnished cage with nest boxes containing artificial turf or grids as nest-floor material and an aviary housing system. Results were log-transformed prior to statistical analyses. For both experiments no systematic differences were found between the conventional cage and furnished cage. The type of nest-floor material in the nest boxes of the furnished cages also did not systematically influence the bacterial contamination. A possible seasonal influence on contamination with a decrease in the winter period (up to > 0.5 log cfu/eggshell) of total count of aerobic and Gram-negative bacteria was observed in the first experiment. The contamination with total aerobic flora was higher (more than 1.0 log) on eggs from the aviary housing system compared to the conventional and the furnished cage systems. For Gram-negative bacteria this was not the case. During the entire period of both experiments, independent of housing system, shell contamination was not influenced by age of hens or period since placing the birds in the houses. For the total count of aerobic bacteria a restricted positive correlation (r2 = 0.66) was found between the concentration of total bacteria in the air of the poultry houses and initial shell contamination.

Air Microbiology↗

PubMed2005

Risk factors associated with Salmonella enterica subsp. enterica contamination of chicken carcases in Senegal.

The objective of this study was to identify the risk factors for Salmonella spp. contamination of Senegalese chicken carcases during slaughtering. One hundred and twenty traditional slaughterhouses were studied from January 2000 to December 2002 in and around Dakar. A questionnaire was administered to the slaughterers and samples of breast skin were taken to assess the Salmonella spp. status of chicken carcases. Results showed that 43.3% of the chicken batches were contaminated with Salmonella spp., with Salmonella Hadar and Salmonella Brancaster as the two main serovars. Salmonella spp. contamination of the live birds before slaughtering was related to contamination of the carcases after slaughtering. Feed withdrawal before slaughtering and thorough cleaning and disinfection procedures decreased the risk of Salmonella contamination. One individual worker for each slaughtering stage was also associated with a decreased risk of Salmonella contamination. Using scalding water for plucking increased the risk of contamination. These results will help slaughterers to produce safer products for local consumers.

Abattoirs↗

PubMed2004

Effect of contaminated preprocessed semen on fertilization rate and embryo quality in assisted reproductive techniques.

We aimed to identify the sources and prevalence of semen contamination from mastrubation and determine the effect of bacterospermia on fertilization rate and embryo quality in standard in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI). This was a prospective controlled study, in an IVF unit of a university teaching hospital, of 93 consecutive couples undergoing IVF-embryo transfer cycles. We evaluated handwashing; semen collection and processing; and assisted reproductive technology using semen provided by masturbation. The main outcome measures were presence and type of micro-organisms in the semen samples and embryo culture medium; the effect of hand washing on rate of contamination; and the effect of semen contamination on fertilization rate and embryo quality. The first consecutive 52 men of the 93 couples were not instructed to wash their hands before masturbation, and the remainder were so instructed. Forty-nine semen cultures (94.2%) in the first group were contaminated compared to only 16 (39%) in the second (p < 0.016); 27 of the 65 positive cultures (41.5%) were contaminated by more than one organism. The most common contaminators were bacteria usually found on the skin. All but four embryo medium cultures were negative. There was no significant difference in fertilization rate and embryo quality by culture findings in either the IVF or the ICSI procedures. We found that a high percentage of manually obtained semen for standard IVF or ICSI procedures was contaminated, but this had no effect on fertilization rate and embryo quality.

Adult↗

PubMed1990

Mobility of polychlorinated aromatic compounds in soils contaminated with wood-preserving oil.

Greater understanding of the mobility of polychlorinated aromatic compounds in soils is needed to investigate contamination and design suitable remediation strategies for sites contaminated with wood-preserving oil. The objectives of this study were (1) to develop a suitable aqueous batch extraction method for soil containing wood-preservative residues; (2) to determine partition coefficients for the primary contaminants [pentachlorophenol (PCP), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFS)] in oil, soil, and aqueous phases; and (3) to evaluate the potential soil migration of the primary contaminants. In a three-phase oil-soil-water mixture, PCP, PCDDs, and PCDFs were partitioned to the greatest extent in the oil phase. These results suggest that the migration of contaminants can occur in a saturated subsurface soil zone containing an oil phase at a wood-preserving site. In the absence of a free oil phase, PCDDs and PCDFs were highly partitioned onto soil and were considered non-leachable in the aqueous phase. However, PCP was considered highly leachable from contaminated soil containing only an aqueous liquid phase. Results from this study indicate that removal of any free oil phase present in subsurface soil should have highest priority during the cleanup of contaminated wood-preserving sites.

Oils↗

PubMed2002

Volatilization of contaminants from suspended sediment in a water column during dredging.

Remedial dredging of contaminated bed sediments in rivers and lakes results in the suspension of sediment solids in the water column, which can potentially be a source for evaporation of hydrophobic organic compounds (HOCs) associated with the sediment solids. Laboratory experiments were conducted in an oscillating grid chamber to simulate the suspension of contaminated sediments and flux to air from the surface of the water column. A contaminated field sediment from Indiana Harbor Canal (IHC) and a laboratory-inoculated University Lake (UL) sediment, Baton Rouge, LA, were used in the experiments, where water and solids concentration and particle size distribution were measured in addition to contaminant fluxes to air. A transient model that takes into account contaminant desorption from sediment to water and evaporation from the water column was used to simulate water and sediment concentrations and air fluxes from the solids suspension. In experiments with both sediments, the total suspended solids (TSS) concentration and the average particle diameter of the suspended solids decreased with time. As expected, the evaporative losses were higher for compounds with higher vapor pressure and lower hydrophobicity. For the laboratory-inoculated sediment (UL), the water concentrations and air fluxes were high initially and decreased steadily implying that contaminant release to the water column from the suspended solids was rapid, followed by evaporative decay. For the field sediments (IHC), the fluxes and water concentrations increased initially and subsequently decreased steadily. This implied that the initial desorption to water was slow and that perhaps the presence of oil and grease and aging influenced the contaminant release. Comparison of the model and experimental data suggested that a realistic determination of the TSS concentration that can be input into the model was the most critical parameter for predicting air emission rates.

Engineering↗

PubMed2006

Effects of contamination age on phenanthrene desorption from aquifers.

The length of contact time of contaminant with aquifer solids has a significant impact on the subsequent desorption process that normally occurs after the aquifer cleanup. In the present study, a diffusion model was built and validated with experimental results. Phenanthrene was brought in contact with sand and soil particles for different lengths of time. The distributions of solid-phase concentration within intraparticle pores were determined numerically and then used as the initial conditions for the subsequent desorption process. The purpose was to investigate the effect of contaminants' age on desorption time. Results revealed that a significant fraction of contaminants desorbs very slowly, even for freshly contaminated materials. For example, it has taken years for phenanthrene to release from freshly contaminated Jurassic limestone and Triassic limestone. The desorption time for aged contaminated material was found to be longer than for freshly contaminated material, at a more or less constant ratio with respect to the degree of aging.

Adsorption↗

PubMed2005

A laboratory and pilot study of thermally enhanced soil vapor extraction method for the removal of semi-volatile organic contaminants.

Laboratory and field pilot study was conducted to evaluate the effectiveness of thermally enhanced soil vapor extraction (SVE) system for the removal of semi-volatile organic contaminants (SVOCs) from soils. Several parametric studies were conducted to evaluate the effect of temperature and air flow rate on the removal of SVOCs. Column studies near ambient temperature show very little efficiency for SVOCs removal. The removal rates of SVOCs are highly dependent on temperature. Moving fronts in the effluent concentrations of contaminants are observed, according to the order of volatility of contaminant. This result is attributed to continuous changes in the liquid composition toward less volatile fractions, thus increasing the mole fraction of the less volatile fractions remaining in the liquid mixture. It is also found that increased air flow rate results in high removal rate of contaminants. However, too high air flow rate brings about the mass transfer limitation on the volatilization of the contaminants. Results from steady-state column studies show that mass transfer limitation is reduced at high temperature, possibly due to the increase in the diffusivity of contaminant in the liquid and gas phase. A field pilot study of a hot air injection method for the remediation of diesel-contaminated soil has shown advantages over the conventional SVE. Within 30 days of test operation, TPH concentrations at unsaturated soils were dramatically reduced, corresponding to more than 95% removal. However, temperature profiles and the removal rates of SVOCs near groundwater level indicate that moisture content would be a limiting factor in the real application of hot air injection.

Air Movements↗

PubMed2003

Contamination of bone marrow products with an actinomycete resembling Microbacterium species and reinfusion into autologous stem cell and bone marrow transplant recipients.

Bacterial contamination of bone marrow or peripheral blood stem cell transplant products typically occurs with skin flora or, rarely, gram-negative organisms. We describe a clonal outbreak of contamination in transplant products caused by contamination with an aerobic actinomycete that occurred at our institution during the summer of 2001. From 1 July through 12 September 2001, 73 peripheral blood or bone marrow stem cell products were obtained from 39 patients, and 34 products were found to be contaminated with the outbreak strain. Fourteen patients were reinfused with contaminated cells, and the outbreak strain was isolated from the blood cultures for one patient. Investigation revealed multiple potential sources for contamination during the product cryopreservation process. The outbreak of contamination was aborted upon modification of the cryopreservation process.

Actinobacteria↗

PubMed2002

Skin antisepsis kits containing alcohol and chlorhexidine gluconate or tincture of iodine are associated with low rates of blood culture contamination.

OBJECTIVE: Skin preparation is an important factor in reducing the rate of blood culture contamination. We assessed blood culture contamination rates associated with the use of skin antisepsis kits containing either 2% alcoholic chlorhexidine gluconate or 2% alcoholic tincture of iodine. DESIGN: Prospective, blinded clinical trial. SETTING: Tertiary-care teaching hospital. PATIENTS: Adult patients in medical wards, the medical intensive care unit, and the cardiac intensive care unit who needed paired, percutaneous blood cultures. INTERVENTIONS: House officers, medical students, and healthcare technicians drew the blood for cultures. We prepared sacks containing all of the necessary supplies, including two different types of antiseptic kits. In each sack, one kit contained 2% chlorhexidine in 70% isopropyl alcohol and the other contained 2% tincture of iodine in ethyl alcohol and 70% isopropyl alcohol. Each patient received chlorhexidine at one site and tincture of iodine at the other. RESULTS: Four (0.9%) of 430 blood culture sets from 215 patients were contaminated. The contamination rate when using alcohol and chlorhexidine (1 of 215, 0.5%) did not differ significantly from the contamination rate when using tincture of iodine (3 of 215, 1.4%; P = .62, McNemar test). There was an 87% probability that the two interventions differed by less than 2% in their rate of contamination. CONCLUSIONS: Both of these antiseptic kits were highly effective for skin preparation prior to drawing blood for cultures. The use of these kits may have contributed to the low contamination rate observed in this study.

2-Propanol↗

PubMed2000

Breast tumor contamination of peripheral blood stem cell harvests: increased sensitivity of detection using immunomagnetic enrichment.

Contaminating tumor cells in peripheral blood stem cell (PBSC) grafts infused for hematopoietic rescue after high-dose chemotherapy could potentially contribute to relapse in BrCa patients. To date the prevalence of PBSC contamination in BrCa patients, as determined by standard immuno-cytochemistry (ICC) assays, has generally been found to be relatively low. However, assay sensitivity may have an important impact on the ability to detect contamination. In this investigation a novel and highly sensitive BrCa cell assay using immunomagnetic enrichment with a panel of antiBrCa monoclonal antibodies (MAbs) and detection by ICC has been characterized. The immunomagnetic enrichment with ICC detection (IE-ICC) assay was directly compared with standard ICC in ability to detect BrCa contamination of PBSC specimens from patients with high-risk stage II/III and metastatic disease. The sensitivity of the IE-ICC assay was approximately 50-fold greater than that of standard ICC. As determined by standard ICC assay, BrCa cells were present in 1/14 patients (7%) and 2/26 (8%) specimens. In contrast, with IE-ICC assay the proportions of positive findings in patients (12/14, 86%) and specimens (19/26, 73%) were significantly higher (p = 0.001 and p < 0.0005, respectively). These preliminary findings suggest that the prevalence of PBSC contamination may be substantially higher than previously appreciated. Consequently, measures to reduce tumor contamination in the graft may have the potential to improve patient outcomes. Higher sensitivity assays such as the IE-ICC assay may play an important role in assessing the risks associated with tumor contamination and the effectiveness of tumor-purging approaches such as positive selection of CD34+ cells and in monitoring patient response to therapy.

Antibodies, Monoclonal↗

PubMed2003

Cytotoxic drug contamination on the outside of vials delivered to a hospital pharmacy.

We recently carried out a study of two UK hospital pharmacy units preparing cytotoxic drugs using isolators that showed low level contamination on floor surfaces and disposable gloves worn by staff. It has been suggested that this level of contamination may be related to some level of contamination on the drug vials as delivered from manufacturers rather than leakage from the isolators. We have investigated the level of cytotoxic drug contamination on the external surfaces of the drug vials as delivered to a hospital pharmacy stores. We monitored 30, randomly chosen vials for the drugs cisplatin, carboplatin, cyclophosphamide, ifosfamide and methotrexate using well-established methods. A 0.5 m2 floor area directly in front of the shelves used for storing the cytotoxic drugs was also wipe sampled and the disposable gloves worn while wiping the vials for each drug were also analysed. A significant number of vials had a quantifiable level of external contamination. Levels of contamination up to 344 ng/vial were found. Levels of glove and floor contamination for some drugs were found to be comparable with values found in our study of the clean rooms where the isolators were situated and the pharmacy staff prepared the cytotoxic drugs.

Antineoplastic Agents↗

PubMedDate not supplied

Cocaine contamination of United States paper currency.

The exchange of illicit cocaine for money by drug dealers is an everyday occurrence in cities in the United States. There is ample opportunity during the exchange, storage, and use of cocaine for paper currency to become contaminated. Because currency is exchanged frequently, it is likely that contaminated currency would be found in common use. We examined ten single dollar bills from several cities in the United States for the presence of cocaine. Individual bills were extracted with methanol (10 mL). Cocaine was purified from the methanol extract by solid-phase extraction (SPE). The SPE extract was analyzed by gas chromatography-mass spectrometry (GC-MS). Standard curves were constructed with new, uncirculated currency. Cocaine was identified qualitatively by full scan and quantitated by selected ion monitoring. Cocaine was present in 79% of the currency samples analyzed in amounts above 0.1 micrograms and in 54% of the currency in amounts above 1.0 micrograms. Contamination was widespread and was found in currency from all sites examined. Cocaine amounts were highly variable and ranged from nanogram to milligram amounts. The highest amount of cocaine detected on a single one-dollar bill was 1327 micrograms. These results indicated that cocaine contamination of currency is widespread throughout the United States and is likely to be primarily a result of cross-contamination from other contaminated currency and from contaminated money-counting machines.

Cocaine↗

PubMed1991

Risk of blood contamination and injury to operating room personnel.

The potential for transmission of deadly viral diseases to health care workers exists when contaminated blood is inoculated through injury or when blood comes in contact with nonintact skin. Operating room personnel are at particularly high risk for injury and blood contamination, but data on the specifics of which personnel are at greater risk and which practices change risk in this environment are almost nonexistent. To define these risk factors, experienced operating room nurses were employed solely to observe and record the injuries and blood contaminations that occurred during 234 operations involving 1763 personnel. Overall 118 of the operations (50%) resulted in at least one person becoming contaminated with blood. Cuts or needlestick injuries occurred in 15% of the operations. Several factors were found to significantly alter the risk of blood contamination or injury: surgical specialty, role of each person, duration of the procedure, amount of blood loss, number of needles used, and volume of irrigation fluid used. Risk calculations that use average values to include all personnel in the operating room or all operations performed substantially underestimate risk for surgeons and first assistants, who accounted for 81% of all body contamination and 65% of the injuries. The area of the body contaminated also changed with the surgical specialty. These data should help define more appropriate protection for individuals in the operating room and should allow refinements of practices and techniques to decrease injury.

Blood↗

PubMed2001

Bacterial contamination of human organ-cultured corneas.

PURPOSE: The aim of this study was to detect and identify bacterial contaminants in human corneoscleral tissue after organ culture storage. METHODS: Seventy-two corneoscleral rims and corneal buttons trephined from organ cultured corneoscleral discs using aseptic technique and 45 organ-cultured donor corneoscleral rims postpenetrating keratoplasty) were subjected to a mechanical extraction technique using a Stomacher laboratory blender. As a control, 28 of the corneoscleral rims and buttons were halved; one half of each corneoscleral rim and button was decontaminated in formalin for 48 hours before thorough washing in balanced salt solution. Corneal specimens, culture medium, and transport (5% dextran) medium were cultured in brain-heart infusion broth at 37 degrees C for 5 days. Bacterial isolates were identified after culture of turbid enrichment broth. RESULTS: Bacterial contamination was demonstrated in 29% (21 of 72) of the corneoscleral rims and 15% (11 of 72) of the corneal buttons that were trephined aseptically from corneoscleral discs and in 29% (13 of 45) of postkeratoplasty corneoscleral rims. Bacterial contaminants were not isolated from controls. Isolated microorganisms included coagulase-negative Staphylococcus, Staphylococcus aureus, Streptococcus viridans, Pseudomonas sp, and Bacillus sp. A correlation was not demonstrated between contamination and cause of death, death to enucleation, death to culture time, or time in culture. Postkeratoplasty endophthalmitis was not evident in the patients who had received corneal buttons from those corneoscleral discs that had contaminated corneoscleral rims. CONCLUSIONS: Bacterial contamination exists in corneoscleral tissue after organ culture storage. The difference in distribution of bacteria and percentage of contamination between the peripheral and central corneas causes us to question the value of routine postpenetrating keratoplasty corneoscleral rim cultures.

Bacteria↗

PubMed1998

Radioactive contamination incidents involving protective clothing.

The study focuses on incidents at Department of Energy facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work; (2) working conditions; (3) type of anti-contamination material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-contamination clothing most often identified was cotton or water-resistant disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled.

Databases, Factual↗

PubMed2002

A case of repeated accidental inhalation contamination of a male subject with 137Cs.

Two consecutive incidents of internal contamination occurred within a 13-mo period when a male worker (56 y, 70 kg) briefly entered and stayed (during a breakdown of control apparatus for air contamination) in a radioisotope storeroom with air contaminated by an explosion of old ampules containing 137Cs solution. Monitoring of the first contamination began on day 34 and that of the second one within 1 h after inhalation. According to the two-exponential model, long-term biological half-times of 92 and 93 d were obtained for the first and second contaminations, respectively. The short-term biological half-time for the second contamination was calculated as 3.0 d. The mean value of the fraction of 137Cs excreted in daily urine to that in total excreta was 0.88 for the first contamination and 0.89 for the second one.

Accidents, Occupational↗