Inability of GSTT1 to activate iodinated halomethanes to mutagens in Salmonella

Drinking water disinfection by-products (DBPs), including the ubiquitous trihalomethanes (THMs), are formed during the treatment of water with disinfectants (e.g., chlorine, chloramines) to produce and distribute potable water. Brominated THMs (Br-THMs) are activated to mutagens via glutathione S-transferase theta 1 (GSTT1); however, iodinated THMs (I-THMs) have never been evaluated for activation by GSTT1. Among the I-THMs, only triiodomethane (iodoform) has been tested previously for mutagenicity in Salmonella and was positive (in the absence of GSTT1) in three strains (TA98, TA100, and BA13), all of which have error-prone DNA repair (pKM101). We evaluated five I-THMs (chlorodiiodomethane, dichloroiodomethane, dibromoiodomethane, bromochloroiodomethane, and triiodomethane) for mutagenicity in Salmonella strain RSJ100, which expresses GSTT1, and its homologue TPT100, which does not; neither strain has pKM101. We also evaluated chlorodiiodo-, dichloroiodo-, and dibromoiodo-methanes in strain TA100 +/- rat liver S9 mix; TA100 has pKM101. None was mutagenic in any of the strains. The I-THMs were generally more cytotoxic than their brominated and chlorinated analogues but less cytotoxic than analogous trihalonitromethanes tested previously. All five I-THMs showed similar thresholds for cytotoxicity at ~2.5 μmoles/plate, possibly due to release of iodine, a well-known antimicrobial. Although none of these I-THMs was activated by GSTT1, iodoform appears to be the only I-THM that is mutagenic in Salmonella, only in strains deficient in nucleotide excision repair (uvrB) and having pKM101. Given that only iodoform is mutagenic among the I-THMs and is generally present at low concentrations in drinking water, the I-THMs likely play little role in the mutagenicity of drinking water.

[Asthma induced by chloramine T in nurses: case report]

BACKGROUND

Chloramine T is used in hospitals as a disinfectant and for sterilization of endoscopy instruments.

OBJECTIVES

A case of a nurse suffering from asthma due to Chloramine T is presented in order to focus attention on this occupational disease.

METHODS AND RESULTS

The patient (male, 43 years) had been a nurse since 1993, working in various departments and operating rooms where he was exposed to glutaraldehyde and Chloramine T to disinfect surgical and endoscopy instruments. In 2007 he noticed the beginning of asthmatic reactions after exposure to the disinfectant. Skin tests with common allergens gave positive reactions and a skin test with Chloramine T gave a positive result. An inhalation test with glutaraldehyde gave negative results for both asthma and rhinitis. During the inhalation test with Chloramine T 0.5%, a significant biphasic decrease in FEVI was observed. The score of subjective symptoms for rhinitis was negative,

CONCLUSIONS

The case confirms the current difficulty in diagnosing occupational asthma due to Chloramine T in health care workers, which is due to the frequent presence of late reactions and to exposure to several respiratory allergens and irritants in the workplace. The specific inhalation challenge is thus confirmed as the gold standard for the diagnosis of asthma induced by Chloramine T and in occupational asthma in general. It may very well be that the frequency of occupational asthma due to sensitization to Chloramine T in nurses is underestimated.

[Genotoxicity of drinking water during chlorine and chloramine disinfection and the influence of disinfection conditions using the umu-test]

In this study, the effects of disinfectant dosage, reaction time and the ratio of Cl2 to N of disinfectant on genotoxicity of effluent of ozone-biological activated carbon (O3-BAC) during chlorine or chloramine disinfection were investigated using umu-test. It was found that, the genotoxicity of effluent of O3-BAC before disinfection ranged from 20-70 ng/L, and it increased after disinfection by chlorine or chloramines. With the same reaction time(24 h), genotoxicity after chlorination (40-95 ng/L) was higher than that after chloramination (20-40 ng/L) under same initial dosage. For chlorination, with initial dosage increasing from 0 mg/L to 10 mg/L, genotoxicity increased firstly, and got the maximum value at about 0.5-1 mg/L dosage, then decreased and got the minimum value at about 3-5 mg/L dosage, and finally increased again. For chloramination, genotoxicity didn't change that much. With the dosage of 3 mg/L and reaction time increasing from 0 h to 72 h, no matter for chlorine or chloramines disinfection, genotoxicity of effluent of O3-BAC both increased firstly, and got the maximum value at about 2 h, then decreased and got the minimum value at about 18 h, and finally increased again, and genotoxicity after chlorine disinfection (83-120 ng/L) was higher than that after chloramines disinfection (20-62 ng/L) under same reaction time. Further more, effects of the different ratios of Cl2 to N of disinfectant on genotoxicity of effluent of O3-BAC were also studied. Results of this study demonstrate that under test conditions, chloramine disinfection is safer than chlorine disinfection in the aspect of genotoxicity for drinking water, and the changes of genotoxicity are different from those of total HAAs.

[Disinfection by-products reduction of combined disinfection by chlorine and monochloramines in distribution system]

Halogen disinfection by-products of four chlorined disinfection processes with long contact time in distribution system was compared in the work. These four disinfection processes are free chlorine, monochloramines, free chlorine disinfection in clearwelles while chloramines in distribution system, sequential chlorination disinfection with short-term free chlorine plus chloramines. According to the research, free chlorine generates most trihalomethanes (THMs) and haloacetic acids (HAAs) both in clearwells and distribution system, while monochloramines barely yield halogen DBPs. Free chlorine disinfection in clearwelles while chloramines in distribution system could reduce 9.6% of THMs and 42% of HAAs in 24 h contact time of distribution system compared with free chlorine. But free chlorine has contacted with water for 2 h in this process, halogen DBPs have been yielded substantially. Process of sequential chlorination disinfection could control DBPs more effectively due to keeping a short contact time of free chlorine and water. 48% of THMs and 72% of HAAs are reduced in 24h compared with free chlorine. In conclusion, sequential chlorination disinfection is a more effective disinfection process for controlling DBPs and water safety.

Comparison of bond strength using various fixation methods

The purpose of this study was to compare different solutions for the storage of teeth and their influence on the enamel surface. The bond strength of bonded brackets on the enamel surface was determined by shear testing with an Instron measuring machine (feed rate 0.5 mm/min). Previously, these teeth had been stored in different solutions and their bond strengths were compared to the values of freshly extracted teeth. The statistical depiction was performed by means of descriptive and explorative data analysis. The analysis was carried out with the SPSS program. For group comparison purposes, the single-factor variance analysis (ANOVA) and the Post Hoc Test (Tukey HSD) were used. The level of significance was set at P < .05. The study showed that bond strength using formaldehyde fixation came closest to bond strength from freshly extracted teeth, so a formaldehyde solution should be used for storage. Only bond strength with teeth stored in thymol was significantly different (P = .02) from that observed with freshly extracted teeth.

Heterogeneous dermatitis complaints after change in drinking water treatment: a case report

BACKGROUND

The disinfectant monochloramine minimizes the formation of potentially hazardous and regulated byproducts, and many drinking water utilities are shifting to its use.

CASE PRESENTATION

After a drinking water utility serving 2.4 million people switched to monochloramine for residual disinfection, a small number of residents complained of dermatitis reactions. We interviewed 17 people about their symptoms. Skin appearance, symptoms, and exposures were heterogeneous. Five respondents had history of hives or rash that preceded the switch to monochloramine.

CONCLUSION

The complaints described were heterogeneous, and many of the respondents had underlying or preexisting conditions that would offer plausible alternative explanations for their symptoms. We did not recommend further study of these complaints.

Tolerability and efficacy of N-chlorotaurine in comparison with chloramine T for the treatment of chronic leg ulcers with a purulent coating: a randomized phase II study

BACKGROUND

The well-known active chlorine compound chloramine T (CAT) with broad-spectrum antimicrobial activity is in common therapeutic use for leg ulcers with purulent coatings; however, this treatment is painful. The tolerability of the less aggressive N-chlorotaurine (NCT), an endogenous compound also produced in vivo by stimulated human granulocytes, could be superior.

OBJECTIVES

To assess the tolerability and efficacy of NCT in the cleaning of purulent coatings in chronic leg ulcers in comparison with CAT.

METHODS

In a double-blind, randomized phase IIb clinical study 40 patients were treated for a median of 7 days (range 3-14) with a 1% aqueous solution of either NCT (20 subjects) or CAT (20 subjects) by twice-daily application of dressings soaked in the test solutions. Criteria for evaluation of tolerability were intensity and duration of pain caused by the ulcer therapy and scores of tissue toxicity (necrosis, granulation tissue and re-epithelialization). Therapeutic efficacy was graded as scores of intensity of purulent coating of the ulcers.

RESULTS

The concentration tolerated in vitro by human epidermoid carcinoma cells was at least 10-fold higher for NCT (0.01%) compared with CAT (0.0001-0.001%). There was significantly less pain caused by NCT compared with CAT (P < 0.05) on days 1 and 4 and a trend for a shorter duration of pain (P = 0.093). The scores of intensity of coating improved without difference in both treatment groups, whereas granulation and re-epithelialization appeared earlier in the NCT group (P < 0.05). Non-quantitative microbiological cultures from ulcer smears revealed persistence of colonization by bacterial species in approximately half of both treatment groups.

CONCLUSIONS

Both active chlorine compounds were helpful in reducing purulent coatings. Because of its lower toxicity and better tolerability, NCT is of advantage in the treatment of leg ulcers.

Occupational asthma caused by chloramines in indoor swimming-pool air

The first series of three workers who developed occupational asthma following exposure to airborne chloramines in indoor chlorinated swimming pools is reported. Health problems of swimmers in indoor pools have traditionally been attributed to the chlorine in the water. Chlorine reacts with bodily proteins to form chloramines; the most volatile and prevalent in the air above swimming pools is nitrogen trichloride. Two lifeguards and one swimming teacher with symptoms suggestive of occupational asthma kept 2-hourly measurements of peak expiratory flow at home and at work, analysed using the occupational asthma system (OASYS) plotter, and/or had specific bronchial challenge testing to nitrogen trichloride, or a workplace challenge. Air measurement in one of the pools showed the nitrogen trichloride levels to be 0.1-0.57 mg x m(-3), which was similar to other studies. Two workers had peak expiratory flow measurements showing occupational asthma (OASYS-2 scores 2.88 and 3.8), both had a positive specific challenge to nitrogen trichloride at 0.5 mg x m(-3) with negative challenges to chlorine released from sodium hypochlorite. The third worker had a positive workplace challenge. Swimming-pool asthma due to airborne nitrogen trichloride can occur in workers who do not enter the water because of this chloramine. The air above indoor swimming pools therefore needs to be assessed and managed as carefully as the water.

Occupational respiratory hypersensitivity in dental personnel

OBJECTIVE

The aim was to study the causes of respiratory hypersensitivity in dental personnel based on the statistics of the Finnish Register of Occupational Diseases (FROD; 1975-1998) and the patient material of the Finnish Institute of Occupational Health (FIOH; 1990-1998).

METHODS

Details about the cases of respiratory hypersensitivity were compiled from the FROD. The occupational rhinitis diagnoses studied at the FIOH were based on work-related symptoms and a change in the status of the nasal mucosa during challenge testing; and the diagnosis of occupational asthma based on reactions in challenge testing, or on IgE positivity and peak flow monitoring at work and during days off.

RESULTS

A total of 64 cases of occupational respiratory diseases (ORDs) was diagnosed in dental personnel during 1975 to 1998 according to the FROD; two cases in 1975 to 1989, and 62 in 1990 to 1998. Twenty-eight cases were of occupational asthma (18 caused by methacrylates), 28 occupational rhinitis (six caused by methacrylates), seven allergic alveolitis and one organic dust toxic syndrome (ODTS). The non-acrylate-material diagnosed in 1990-1998 at the FIOH comprised three cases of asthma and one of rhinitis caused by chloramine-T (sodium- N-chlorine- p-toluene sulphonamide); as well as one case of asthma, seven cases of rhinitis, and two cases of combined rhinitis and conjunctivitis caused by natural rubber latex (NRL). Furthermore, one case of occupational rhinitis caused by Nobetec containing colophony was diagnosed. The incidence rate (IR) of ORD increased from 0 in 1988 to a peak of 105.1 new cases per 100,000 working years in 1995. During the last observation year, i.e. 1998, the IR was 55 new cases per 100,000 workers. The IR in dental personnel was lower than in the whole working population in Finland up until 1992, but since then has been greater than in the whole population, peaking in 1995 when the IR of dental personnel was 2.55 times greater than in the whole population.

CONCLUSION

The present study shows the increasing frequency of respiratory hypersensitivity among dental personnel. Besides methacrylates, important causes of respiratory hypersensitivity are NRL and chloramine-T.

Chloramine-induced haemolysis presenting as erythropoietin resistance

BACKGROUND

In December 1996 we identified an outbreak of erythropoietin (rHuEpo) resistance requiring a substantial increase in rHuEpo dosage in one of our four haemodialysis (HD) units. The dialysate chloramine levels in this unit had risen from <0.1 p.p.m. in 1996 to 0.25-0.3 p.p.m. in 1997. In the other three HD units levels remained <0.1 p.p.m. Other parameters of water quality were within accepted standards.

METHODS

Monthly records of haemoglobin level and rHuEpo dose were available for 148 patients between January 1996 and May 1998. Seventy-two patients, with no recognized cause of rHuEpo resistance, were analysed in detail (August 1997 to April 1998). A subgroup of 15 patients was examined for evidence of haemolysis during HD (methaemoglobin and haptoglobin levels, reticulocyte counts and Heinz bodies). Larger carbon columns were installed in December 1997 to effect chloramine removal.

RESULTS

There was an increase in mean methaemoglobinaemia of 23% (P<0.01) and a 21% fall in mean haptoglobin (P<0.01) across HD, although no patient had a reticulocytosis and only one patient with G6PD deficiency had Heinz bodies. Following installation of larger carbon columns there was an 18.6% rise (P<0.001) in mean haemoglobin level and a subsequent 25.0% reduction (P<0.001) in mean rHuEpo dose. Intradialytic changes in methaemoglobin and haptoglobin were abolished. The dialysate chloramine levels fell to < 0.1 p.p.m. Water company records subsequently revealed a sustained twofold increase in mains water chloramine from November 1996.

CONCLUSIONS

This is the first report linking chloramine exposure and rHuEpo resistance, with only subtle signs of haemolysis. Unheralded changes in mains water constituents can directly affect dialysate water quality and clinical outcomes.

Morphometric assessment of epidermal and mucous-biofilm changes caused by exposure of trout to chloramine-T or formalin treatment

Juvenile rainbow trout were exposed to therapeutic concentrations of formalin or chloramine-T to assess the effects of these chemicals on the morphology of the piscine epidermis and its mucous coat. Repeated treatment, once weekly for 4 weeks, with either chemical did not affect the mucous coat of the epithelium or the degree of folding of the basal lamina. However, treated fish had increased numbers of highly dense vesicles within the apical portions of epithelial cells. The epidermal mucous cells of chloramine-T-treated fish were significantly smaller than in controls. This effect was not noted in formalin-treated fish. Treatment with either chemical resulted in a significantly thinned epidermis. It is concluded that although chloramine-T and formalin may continue to be useful in the aquaculture industry they cause potentially harmful alterations to fish skin.

Effects of subchronic exposure of monochloramine in drinking water on male rats

A subchronic rat study with paired-water control was conducted to resolve the question of whether monochloramine at 200 ppm in drinking water can cause reduced body weight gain and other changes observed in earlier investigations. Male Sprague-Dawley rats (93 +/- 5 g) were divided into three groups of 10 rats each: the treatment group was fed drinking water containing 200 ppm monochloramine, the control group was fed bicarbonate-buffered water ad libitum, and the paired-water control rats were given a daily volume of bicarbonate-buffered water equal to that consumed by the monochloramine treatment group. Compared to the control group, rats in the treatment group consumed an average of 42% less fluid and 16% less food over the 13-week treatment period and had 15-20% lower final body weight gain. Similar degrees of reduction in food consumption and body weight gain were observed in the paired-water rats. A decreased liver to body weight ratio occurred in the treatment and paired-water groups. Increased inorganic phosphate, albumin, total protein, and urea nitrogen were detected in sera from both the treatment group and the paired-water groups. The paired-water animals had lower levels of white blood cells and lymphocytes, while the paired-water and monochloramine-treated groups had reduced monocyte counts. Except for a slightly increased response to Con A observed in splenic lymphocytes of the monochloramine-treated rats (versus the paired-water), no significant changes were found in mitogen responsiveness to T cell, B cell, and B plus T cell mitogens or in splenic natural killer (NK) cell activities. There were no significant changes in serum levels of IgG, IgA, and IgM. The following biochemical parameters showed no significant variations among the three groups: serum thyroxin, liver phase I (PROD, EROD, and MROD) and phase II (UDPGT and GST) drug-metabolizing enzyme activities; serum and liver thiobarbituric acid-reactive substances (TBARS); bronchoalveolar lavage fluid protein and N-acetylgluosaminidase (NAGA) activity; and urinary ascorbic acid, protein, and NAGA activity. Histopathological examination revealed minimal to mild adaptive changes in the liver of the paired-water and monochloramine-treated rats and in the thyroid of the monochloramine-treated animals. No treatment-related cytological changes were found in red cells and bone marrow. The results indicate that the reduced body weight gain and the minor biochemical, hematological, immunological, and histopathological changes associated with subchronic exposure to 200 ppm monochloramine in drinking water (equivalent to an intake of 21.6 mg/kg/day) were largely related to the reduced water intake and food consumption and not caused by monochloramine.

Case-control study of bladder cancer and water disinfection methods in Colorado

A population-based case-control study of bladder cancer and drinking water disinfection methods was conducted during 1990-1991 in Colorado. Surface water in Colorado has historically been disinfected with chlorine (chlorination) or with a combination of chlorine and ammonia (chloramination). A total of 327 histologically verified bladder cancer cases were frequency matched by age and sex to 261 other-cancer controls. Subjects were interviewed by telephone about residential and water source histories. This information was linked to data from water utility and Colorado Department of Health records to create a drinking water exposure profile. After adjustment for cigarette smoking, tap water and coffee consumption, and medical history factors by logistic regression, years of exposure to chlorinated surface water were significantly associated with risk for bladder cancer (p = 0.0007). The odds ratio for bladder cancer increased for longer durations of exposure to a level of 1.8 (95% confidence interval 1.1-2.9) for more than 30 years of exposure to chlorinated surface water compared with no exposure. The increased bladder cancer risk was similar for males and females and for nonsmokers and smokers. Levels of total trihalomethanes, nitrates, and residual chlorine were not associated with bladder cancer risk after controlling for years of exposure to chlorinated water.

Effects of drinking water monochloramine on lipid and thyroid metabolism in healthy men

The purpose of this study was to determine whether a 4-week consumption of 1.5L per day of drinking water containing monochloramine at a concentration of 2 ppm (ppm = mg/L) or 15 ppm under controlled conditions would alter parameters of lipid or thyroid metabolism in healthy men. Forty-eight men completed an 8-week protocol during which diet (600 mg cholesterol per day, 40% calories as fat) and other factors known to affect lipid metabolism were controlled. During the first 4 weeks of the protocol, all subjects consumed distilled water. During the second 4 weeks, one-third of the subjects were assigned randomly to drink 1.5 L per day of water containing 2 ppm of monochloramine, to drink 1.5 L per day of water containing 15 ppm monochloramine, or to continue drinking distilled water. Four blood samples were collected from each subject at the end of each 4-week study period. Subjects drinking monochloramine at a concentration of 2 ppm showed no significant changes in total cholesterol, triglycerides, HDL cholesterol, LDL cholesterol, apolipoproteins A1, A2, or B when compared to the distilled water group. Parameters of thyroid function also were unchanged by exposure to monochloramine at this concentration. However, subjects drinking monochloramine at a concentration of 15 ppm experienced an increase in the level of apolipoprotein B. Other parameters of lipid and thyroid metabolism did not change. We conclude that consumption of drinking water containing 2 ppm of monochloramine does not alter parameters of lipid and thyroid metabolism in healthy men. Consumption of water containing 15 ppm monochloramine may be associated with increased levels of plasma apolipoprotein B.

Bronchial asthma due to sensitization to chloramine T

Chloramine T, an organic, highly reactive derivative of chlorine with potent bactericidal properties, is used as a disinfectant in the food industry. Described as an occupational sensitizer in 1945 for the first time, it produces late or dual asthma, occasionally accompanied by fever and leukocytosis, which is mediated by IgE. We present the case of a male dairy worker who, after 4 years of exposure to the product, developed rhinitis and asthma. Skin tests with chloramine T were positive at a concentration of 10 mg/ml, while all other allergens tested negative. RAST detected specific IgE at 12 PRU and bronchial provocation induced immediate and late bronchoconstriction.

Illness in hemodialysis patients after exposure to chloramine contaminated dialysate

In September 1987, patients at an outpatient dialysis center were exposed to chloramine contaminated dialysate when the carbon filter in a recently modified water treatment system failed. Forty-one patients required transfusion to treat the resultant hemolytic anemia. Epidemiologic investigation demonstrated that the mortality rate among dialysis center patients increased during the 5 months after chloramine exposure when compared with the 12 months before chloramine exposure, but no deaths could be attributed to the exposure. Chloramine is commonly used as a disinfectant in municipal water supplies, and has previously been reported to cause hemolytic anemia in patients undergoing dialysis. Hemodialysis centers in cities that use chloramine in water supplies must design water treatment systems with adequate means for removing chloramine and must monitor processed water closely to ensure that chloramine contamination does not occur. Dialysis centers that make changes in their water processing systems should evaluate all components of the system before changes are made, and must ensure that after modifications are made, processed water meets the standards set by the Association for Advancement of Medical Instrumentation.

[Asthma caused by sodium p-toluene-n-chloro-sulfonamide: observations on a clinical case]

We describe the case of a patient exposed to chloramine-T who experienced severe asthmatic symptoms when spraying chloramine-T solutions. The patient used chloramine-T as a sterilising agent in medical facilities. Occupational asthma due to chloramine-T was diagnosed by means of specific bronchial provocation test (occupational type). We stress the risk of exposure to high levels of chloramine-T and the importance of this compound as a cause of occupational asthma.

Type of disinfectant in drinking water and patterns of mortality in Massachusetts

Chlorination has been the major strategy for disinfection of drinking water in the United States. Concern about the potential health effects of the reaction by-products of chlorine has prompted use of alternative strategies. One such method is chloramination, a treatment process that does not appear to have carcinogenic by-products, but may have less potent biocidal activity than chlorination. We examined the patterns of mortality of residents in Massachusetts who died between 1969 and 1983 and lived in communities using drinking water that was disinfected either by chlorine or chloramine. Comparison of type of disinfectant among 51,645 cases of deaths due to selected cancer sites and 214,988 controls who died from cardiovascular, cerebrovascular, or pulmonary disease, or from lymphatic cancer showed small variation in the patterns of mortality. Bladder cancer was moderately associated with residence at death in a chlorinated community (mortality odds ratio = 1.7, 95% confidence interval = 1.3-2.2) in a logistic regression analysis using controls who died from lymphatic cancer. A slight excess of deaths from pneumonia and influenza was observed in communities whose residents drank chloraminated water compared to residents from chlorinated communities, as well as to all Massachusetts residents (standardized mortality ratio = 118, 95% confidence interval = 116-120 for chloraminated communities, and standardized mortality ratio = 98, 95% confidence interval = 95-100 for chlorinated communities). These results are intended to be preliminary and crude descriptions of the relationship under study.(ABSTRACT TRUNCATED AT 250 WORDS)

Plasma vitamin E levels in a chronically hemolyzing group of dialysis patients

Plasma vitamin E levels and the ascorbate cyanide test were assessed in 15 chronic hemodialysis (HD) patients (group A) exposed to persistently elevated chloramine levels in the dialysis water. The vitamin E levels in these patients, who had evidence of oxidant induced hemolytic anemia, were compared to 15 chronic HD patients exposed to low chloramine levels (group B) and 17 controls (group C). Vitamin E levels were found to be significantly lower in group A than in either groups B or C (p less than 0.001). Within group A, levels were lower in those patients who had a positive ascorbate cyanide test (p less than 0.05). Upon removal of chloramines from the dialysis water, vitamin E levels in group A were no longer significantly different from those found in groups B or C.

Granular activated carbon usage in chloramine removal from dialysis water

Chloramines, oxidant compounds used in municipal drinking water as sanitizing agents, potentiate hemolytic anemia when present in dialysate. Thus far, the addition of ascorbic acid to the dialysate and the use of granular activated carbon (GAC) have been the only reliable, practical methods reported for removing chloramines. This is a report on the bench-scale testing of five kinds of GAC from three manufacturers. The performance of 100 g of each carbon was studied in a 2-in-diameter column through which feed-water containing approximately 1.5 mg/L chloramines flowed downward at an average volumetric rate of 140 ml/min. The carbons' experimental capacities for chloramines differed by as much as one order of magnitude. The experimental results were used to estimate the capacity of a 9-in-diameter, 45-in-tall column of the best carbon. These scale-up estimations indicate that this sorbent may safely last through 156 5-h dialyses.

Heinz-body haemolysis in haemodialysed patients caused by chloramines in Sydney tap water

In August 1981, there was an outbreak of Heinz-body-positive haemolytic anaemia among patients who were undergoing dialysis in Sydney Hospital. This appeared to be due to excessive chloramines in and inadequate carbon filtration of, the water used for haemodialysis. After improvement of the carbon filtration system, there have been no further cases of anaemia.

Occupational asthma due to inhalation of chloramine-T. I. Clinical observations and inhalation-provocation studies

Respiratory symptoms developed in 5 patients who were exposed to chloramine-T, a potent disinfectant used in cleaning butcheries, kitchens, and operating theaters. Skin tests, performed in 4 patients, showed an immediate type of wheal and flare reaction followed by a late-type infiltrative reaction. In 3 patients, inhalation tests with chloramine-T were done. 1 patient showed asthmatic bronchial obstruction, immediately after inhalation, followed by a late-type asthmatic reaction after some hours. 2 patients only exhibited late-type reactions, 4-8 h after challenge. The late bronchial response lasted for several hours or even days and was accompanied by leukocytosis in all 3 patients and a slight fever in 1 patient. No evidence of alveolar involvement appeared. Pre-challenge inhalation of cromoglycate in 1 patient ameliorated the late response considerably.

Occupational asthma due to inhalation of chloramine-T. II. Demonstration of specific IgE antibodies

In the sera of patients who developed asthmatic symptoms after exposure to chloramine-T, specific IgE antibodies are demonstrated by a polystyrene tube radioimmunoassay. These antibodies are directed against human serum albumin treated with chloramine-T. Specific antibodies of subclasses IgG1, IgG3 and IgG4 were not found. Histamine release in response to chloramine-T-treated human serum albumin was demonstrated using the peripheral blood leukocytes of one of the patients. To define the antigenic determinant to which the specific IgE antibodies are directed, radioimmunoassay and radioimmunoassay-inhibition studies were performed using several autologous and heterologous chloramine-T-treated proteins. Moreover, the inhibition capacities of chloramine-T and structurally related compounds were also determined. The results of these experiments indicate that the antigenic determinant is formed, at least in part, by the p-toluenesulfonyl group of the chloramine-T molecule.