Environmental contamination with cytotoxic drugs in healthcare using positive air pressure isolators.

Occupational exposure to cytotoxic drugs of hospital personnel involved in their preparation and administration is a major issue: ever since the introduction of protective measures in recent decades, the handling of these drugs has always been referred to as an occupational health hazard. Isolator technology was one of the protective equipments aimed at providing safe handling, but it has not yet been studied regarding contamination. The present study evaluates surface contamination with four cytotoxic drugs [cyclophosphamide (CP), ifosfamide (IF), 5 fluorouracil (5FU) and methotrexate (MTX)] by wipe sampling in two hospital pharmacies. Wipe samples were taken from work surfaces both located inside and outside the isolators. In addition, working gloves, the surface of infusion bags filled with 5FU or CP, and gloves used in simulation of drug administration were analyzed. Contamination was routinely found inside the isolators but rarely outside the isolators, indicating that the isolator technology is offering good protection of the cytotoxic drug handlers as well as the environment during preparation. On the other hand, contamination was found on the surfaces of infusion bags and gloves in contact with infusion bags filled with cytotoxic drugs. Consequently, personal protective equipment is still recommended during the manipulation and administration of the drugs because of potentially contaminated drug vials and final products.

Surface contamination with antineoplastic agents in six cancer treatment centers in Canada and the United States.

The level of contamination by antineoplastic agents in drug preparation and administration areas in cancer treatment centers in Canada and the United States was determined. Sampling locations at three cancer treatment centers in Canada and three centers in the United States were selected (biological safety cabinets, countertops, and floors in and adjacent to preparation areas; tabletops, chairs, and floors in administration areas). A solution of sodium hydroxide (0.03 M) was spread over the surface of each area. The surface was wiped with one or two absorbent tissues, which were then stored in plastic screw-top containers. Samples were stored at -40 degrees C before analysis of ifosfamide content (U.S. centers only) and cyclophosphamide content by gas chromatography in tandem with mass spectroscopy-mass spectroscopy and fluorouracil content by reverse-phase high-performance liquid chromatography with ultraviolet-light detection. Measurable amounts of the antineoplastic agents were detected in 75% of the pharmacy samples and 65% of the administration samples. In general, the levels of contamination were higher in the pharmacy areas than in the drug administration areas. The pharmacy area at the site with the highest number of drug preparations had considerably more drug contamination than the other sites. The results were similar for Canadian and U.S. centers. Substantial levels of contamination from three antineoplastic agents were detected on a variety of surfaces in pharmacy drug preparation areas and drug administration areas in six cancer treatment centers in Canada and the United States.

Drugs hazardous to healthcare workers. Evaluation of methods for monitoring occupational exposure to cytostatic drugs.

We review the literature concerning possible health risks for individuals (e.g. healthcare workers and pharmaceutical plant employees) occupationally exposed to cytostatic drugs. Cytostatic drugs possess toxic properties and may therefore cause mutagenic, carcinogenic and teratogenic effects. Hence, individuals handling these drugs in the course of their employment may face health risks. For this reason, it is important to monitor occupational exposure to these drugs. An overview of exposure monitoring methods is presented and their value is discussed. Most studies involve nonselective methods for biological monitoring and biological effect monitoring, such as the urinary mutagenicity assay and analysis of chromosomal aberrations and sister-chromatid exchanges in peripheral blood lymphocytes. The disadvantages of these biological methods are that their sensitivity is low and it cannot be proved beyond any doubt that the results found were caused by occupational exposure to cytostatic drugs. For occupational health services it is important to have sensitive and specific methods for monitoring exposure to cytostatic drugs. One of the most promising methods seems to be the determination of cyclophosphamide in urine using gas chromatography-tandem mass spectrometry. Several studies have demonstrated exposure to cyclophosphamide and other cytostatic drugs, even when protective measures were taken and safety guidelines were followed. To estimate the magnitude of any health effects arising from this exposure, we calculated the risk of cancer due to occupational exposure to cyclophosphamide on the basis of available human and animal dose-response data and the amounts of cyclophosphamide found in urine. The initial results show an extra cancer risk for pharmacy technicians and nurses.

Exposure of pharmacy technicians to antineoplastic agents: reevaluation after additional protective measures.

In the past, special guidelines and protective measures have been introduced to protect hospital workers during the handling of antineoplastic agents; nevertheless, it was found that they did not prevent the uptake of these toxic compounds. In response, additional protective measures were introduced, including adaptations of the laminar downflow hood, use of special masks, use of double pairs of gloves, and replacement of ampules with vials. In the current study, the authors compared the effects in these additional measures with results of a previous study. Cyclophosphamide, 5-fluorouracil, and methotrexate constituted 81% of the antineoplastic agents prepared; therefore, the investigators monitored these compounds again by personal air sampling and by determining the levels of contamination on masks and gloves. Cyclophosphamide in the urine of workers was also measured. During preparation, investigators concluded that there were lower concentrations of cyclophosphamide in the air than had occurred in the previous study. Replacement of ampules with vials (i.e., 5-fluorouracil) resulted in a significantly diminished contamination of latex gloves. Cyclophosphamide was detected in urine samples provided by six of nine technicians; the maximum amount excreted over 5 d was 2.6 microg. The mean cyclophosphamide excretion/d was not significantly lower than that found in the previous study (0.16 microg and 1.44 microg, respectively). Despite an intensified hygienic regimen, exposure to antineoplastic agents cannot be reduced if the reasons for exposure remain unknown.

Occupational exposure to antineoplastic agents and parameters for renal dysfunction.

To study the nephrotoxic effects of occupational exposure to antineoplastic agents, the early renal effect parameters retinol-binding protein (RBP) and albumin (ALB) were determined in the urine of 11 hospital workers involved in the preparation and administration of antineoplastic agents and in 23 hospital workers not involved in drug handling, who served as nonexposed controls. No significant difference was found between the exposed group and the nonexposed control group with respect to the early renal effect parameters RBP and ALB. Although it was demonstrated that the hospital workers were exposed to cyclophosphamide (CP) and probably other antineoplastic agents, the results of the present study show that these exposure levels did not cause nephrotoxic effects.

Biomonitoring of occupational exposures to cytostatic anticancer drugs.

Cytostatic anticancer drugs are known as carcinogenic, mutagenic, and teratogenic risk factors for health care workers who are occupationally exposed during the preparation and administration of such drugs. During the last 20 years, several researchers have developed and validated methods to monitor occupational exposure to such agents. This paper reviews the literature with respect to the possible effects on occupationally exposed hospital workers and establishing occupational exposure.

Influence of Aroclor 1254, phenobarbital, beta-naphthoflavone, and ethanol pretreatment on the biotransformation of cyclophosphamide in male and female rats.

The aim of the present study is to investigate the influence of the environmental factors, smoking and alcohol, on the biotransformation of cyclophosphamide (CP) in the rat in vivo and in vitro with S9 liver fractions. The biotransformation of CP was studied by the determination of the CP metabolites, nor-nitrogen mustard (NNM), 4-ketocyclophosphamide (KCP), and carboxyphosphamide (CAR). The effect of the environmental factors, smoking and alcohol consumption, on the biotransformation enzymes was mimicked by pretreatment of rats with beta-naphthoflavone and ethanol, respectively. Rats treated with olive oil and water served as controls and rats pretreated with Aroclor 1254 and phenobarbital were used as positive controls. The influence of sex and supplementation with NAD and GSH, mimicking a biological variation in NAD and GSH levels in rat and human liver, was also studied. Pretreatment of rats with Aroclor 1254 decreased the excretion of unmetabolized CP in urine, most likely due to an enhanced biotransformation. The in vitro hepatic biotransformation of CP in rats was strongly influenced by sex, by supplementation with NAD and GSH, and by pretreatment with the enzyme-inducers, phenobarbital and Aroclor 1254. No influence of pretreatment with the enzyme-inducers, beta-naphthoflavone and ethanol, was found. The results suggest that the influence of the environmental factors, alcohol consumption and smoking, on the biotransformation of CP in man will be negligible.

Determination of cyclophosphamide metabolites by gas chromatography and thermionic specific detection. Interindividual differences in hepatic biotransformation of cyclophosphamide in man in vitro.

Sensitive methods for the determination of the cyclophosphamide metabolites nornitrogen mustard, 4-ketocyclophosphamide and carboxyphosphamide are presented. After liquid-liquid extraction and derivatization, the metabolites are determined by gas chromatography and thermionic specific detection. The methods were used to study the in vitro biotransformation of cyclophosphamide with S-9 liver fractions of human donors. The results show large interindividual differences in the formation of nornitrogen mustard and carboxyphosphamide. 4-Ketocyclophosphamide was not detected.

Cancer risk assessment for health care workers occupationally exposed to cyclophosphamide.

In the present study a cancer risk assessment of occupational exposure to cyclophosphamide (CP), a genotoxic carcinogenic antineoplastic agent, was carried out following two approaches based on (1) data from an animal study and (2) data on primary and secondary tumors in CP-treated patients. Data on the urinary excretion of CP in health care workers were used to estimate the uptake of CP, which ranged from 3.6 to 18 micrograms/day. Based on data from an animal study, cancer risks were calculated for a health care worker with a body weight of 70 kg and a working period of 40 years, 200 days a year (linear extrapolation). The life-time risks (70 years) of urinary bladder cancer in men and leukemias in men and women were found to be nearly the same and ranged from 95 to 600 per million. Based on the patient studies, cancer risks were calculated by multiplication of the 10-year cumulative incidence per gram of CP in patients by the estimated mean total uptake in health care workers over 10 years, 200 days a year. The risk of leukemias in women over 10 years ranged from 17 to 100 per million using the secondary tumor data (linear extrapolation). Comparable results were obtained for the risk of urinary bladder tumors and leukemias in men and women when primary tumor data were used. Thus, on an annual basis, cancer risks obtained from both the animal and the patient study were nearly the same and ranged from about 1.4 to 10 per million. In The Netherlands it is proposed that, for workers, a cancer risk per compound of one extra cancer case per million a year should be striven for ("target risk") and that no risk higher than 100 per million a year ("prohibitory risk") should be tolerated. From the animal and the patient study it appears that the target risk is exceeded but that the risk is still below the prohibitory risk.

Urinary cyclophosphamide excretion and chromosomal aberrations in peripheral blood lymphocytes after occupational exposure to antineoplastic agents.

In this study we have compared the results of a method for the detection of cyclophosphamide in urine and the results of analysis of chromosomal aberrations in peripheral blood lymphocytes of four groups of subjects with various exposure statuses. These groups are 17 Dutch and 11 Czech exposed workers (mainly hospital nurses and pharmacy technicians) handling antineoplastic agents and 35 Dutch and 23 Czech controls (nurses, medical doctors, pharmacy and lab technicians) not handling these drugs. The groups were subdivided into smokers and non-smokers because of a confounding effect of smoking. Within the Dutch groups, the percentage of aberrant cells and the number of breaks per cell were increased for smokers compared to non-smokers. The percentage of aberrant cells was increased in Dutch exposed workers in comparison with Dutch control workers. Within the Czech groups the percentage of aberrant cells and the number of breaks per cell were increased in exposed workers in comparison with control workers. However, both Dutch and Czech smokers mainly contributed to the increase. The results suggest an additive effect of exposure and smoking in the Dutch subjects and a more than additive effect in the Czech subjects. In urine samples of three out of 11 Dutch exposed workers cyclophosphamide was found in a range of 0.1-0.5 micrograms/24 h. Higher levels were detected in the urine of eight out of 11 Czech exposed workers, a range of 0.1-2.9 micrograms/24 h. No correlation was observed between the amounts of cyclophosphamide excreted in urine on the one hand and the percentage of aberrant cells and the number of breaks per cell on the other hand. The present study is the first study showing that hospital workers having an increase in chromosome aberrations related to their work are exposed to at least one antineoplastic agent.

Environmental contamination and assessment of exposure to antineoplastic agents by determination of cyclophosphamide in urine of exposed pharmacy technicians: is skin absorption an important exposure route?

In the Netherlands, special guidelines and safety precautions were introduced about 10 y ago for preparation and administration of antineoplastic agents. However, little is known about the effectiveness of these measures. In this study, occupational exposure to antineoplastic agents of nine pharmacy technicians who were involved in drug preparation was investigated. Cyclophosphamide, 5-fluorouracil, and methotrexate accounted for 95% of the antineoplastic agents prepared; therefore, the presence of these compounds was monitored. During preparation, cyclophosphamide was detected in the air of the work environment (< 0.04-10.1 micrograms/m3). Contamination of and permeation through latex gloves were found for each of the three compounds. The uptake of cyclophosphamide was assessed by the determination of cyclophosphamide in urine. The drug was found in urine samples of six pharmacy technicians, including three persons who were not directly involved in the preparation of cyclophosphamide. The amounts excreted ranged from 0.2 to 19.4 micrograms/24 h. The results strongly suggest that inhalation is of minor importance for internal exposure, compared with other, presumably dermal, routes.

Biological and environmental monitoring of occupational exposure of pharmaceutical plant workers to methotrexate.

The exposure of 11 pharmaceutical plant workers to methotrexate (MTX) was studied. Personal air samples were taken during the different manufacturing processes: drug compounding, vial filling, and tablet preparation. The uptake of MTX was established by the determination of MTX in urine. MTX was analyzed using the fluorescence polarization immunoassay (FPIA), a method that is frequently used for monitoring serum levels in patients treated with MTX. The FPIA method was modified in such a way that MTX could be measured quickly and efficiently in air and urine samples. MTX was detected in air samples of all workers except for those involved in the vial filling process (range: 0.8-182 micrograms/m3; median: 10 micrograms/m3). The highest concentrations were observed for workers weighing MTX (118 and 182 micrograms/m3). MTX was detected in urine samples of all workers. The mean cumulative MTX excretion over 72-96 h was 13.4 micrograms MTX-equivalents (range: 6.1-24 micrograms MTX-equivalents). A significantly lower background level of 10.2 micrograms MTX-equivalents was measured in urine of 30 control persons (range: 4.9-21 micrograms MTX-equivalents).

Assessment of occupational exposure of pharmaceutical plant workers to 5-fluorouracil. Determination of alpha-fluoro-beta-alanine in urine.

The exposure of pharmaceutical plant workers, involved in drug compounding and drug production, to 5-fluorouracil (5FU) was studied. 5FU was found by the analysis of air and wipe samples. During weighing, 5FU was detected in the air (75 micrograms/m3). 5FU was also present on the filter of the mask of the weigher (120 micrograms). Before drug compounding 5FU was found on the floor (range, < 1 to 8 ng/cm2; median, 2 ng/cm2). After routine cleaning significant higher amounts of 5FU were measured (range, 70 to 630 ng/cm2; median, 150 micrograms/cm2; P = .02). The amounts of 5FU present on several objects were lower when compared to the amounts on the floor. The gloves used were always contaminated (range, 22 to 720 micrograms/pair of gloves; median, 141 micrograms/pair of gloves). The uptake of 5FU was established by the determination of alpha-fluoro-beta-alanine, the main metabolite of 5FU, in the urine of the workers. Fifty micrograms of alpha-fluoro-beta-alanine were found in urine of the weigher.

Determination of cyclophosphamide in urine by gas chromatography-mass spectrometry.

A sensitive gas chromatographic method for the determination of cyclophosphamide in urine is presented. After liquid-liquid extraction with diethyl ether and derivatization with trifluoroacetic anhydride, cyclophosphamide was identified and quantified with mass spectrometry. The method is suitable for the determination of cyclophosphamide at concentrations of more than 0.25 ng/ml, which enables the uptake of cyclophosphamide during occupational activities, such as the preparation and administration of antineoplastic agents in hospitals, to be measured. Simple preparation makes the method appropriate for routine analysis.

Occupational exposure of animal caretakers to cyclophosphamide.

Little is known about the exposure of animal caretakers to toxic agents during the administration of such chemicals to laboratory animals. In this study, we have investigated the environmental contamination with cyclophosphamide (CP) in an animal laboratory where mice were housed and injected with this compound. Also the contamination of gloves, sleeve protectors, and masks used for personal protection was studied. The uptake of CP by the animal caretakers was determined by the analysis of unmetabolized CP in urine. For the estimation of CP in the air, air samples were taken and filters of the air-circulation system were analyzed. On the filters, amounts of CP were detected corresponding with < 0.1-1.0 microgram/day. Environmental contamination was also measured by analysis of wipe samples taken from different spots (objects and surfaces). The presence of CP was not only observed in the room where the mice were housed and treated with CP but also in adjacent rooms (< 0.02-44 ng/cm2). The gloves used during the injection of CP were always contaminated (2-199 micrograms/pair). No penetration of the gloves was established. The sleeve protectors were incidentally contaminated (< 0.3-10 micrograms) and on the masks no CP was found (< 0.2 microgram). Eighty seven urine samples from four animal caretakers were analyzed for unmetabolized CP. In one sample, CP was detected (0.7 microgram). The results show that in this particular study animal caretakers are exposed to CP during their work.

Detection of contamination with antineoplastic agents in a hospital pharmacy department.

The contamination with fluorouracil, cyclophosphamide and methotrexate was studied in a hospital pharmacy department where these drugs were prepared. In the preparation room, air samples were taken before and during preparation of the drugs. Methotrexate was detected in one sample which was collected during preparation (0.3 micrograms/m3). Spot samples were taken in the vertical laminar airflow safety hood before and after preparation of the drugs and after cleaning of the hood. Contamination of the laminar airflow hood was: cyclophosphamide: 1-160 ng/cm2; fluorouracil: 10-62 ng/cm2 and methotrexate: 2-633 ng/cm2. Spot samples from the floor in front of and beneath the laminar airflow hood showed contamination with especially fluorouracil (48-236 micrograms/m2). The gloves used during preparation of the drugs were contaminated mainly with fluorouracil (5-980 ng/cm2). Urine samples from two workers involved in the preparation of the drugs were analysed for unmetabolized cyclophosphamide; it was not detected. Although no uptake of cyclophosphamide was established, it is shown that the methods for measurement of cyclophosphamide, fluorouracil and methotrexate in the preparation room are applicable for the control of occupational exposure to these drugs.

Occupational exposure to antineoplastic agents at several departments in a hospital. Environmental contamination and excretion of cyclophosphamide and ifosfamide in urine of exposed workers.

The occupational exposure to cyclophosphamide (CP), ifosfamide (IF), 5-fluorouracil (5FU), and methotrexate (MTX) of 25 pharmacy technicians and nurses from four departments of a hospital was investigated. Previously developed methods for the detection of exposure to some antineoplastic agents were validated. Exposure to CP, IF, 5FU, and MTX was measured by the analysis of these compounds in the environment (air samples and wipe samples from possible contaminated surfaces and objects). Contamination of the work environment was found not only on the working trays of the hoods and on the floors of the different rooms but also on other objects like tables, the sink unit, cleaned urinals and chamber pots, and drug vials and ampules used for preparation and packing of drugs. The gloves used during preparation of the drugs and during cleaning of the hoods were always contaminated. The uptake of CP or IF was determined by the analysis of both compounds in urine. CP or IF was detected in the urine of eight pharmacy technicians and nurses. The amounts ranged from less than 0.01 to 0.5 micrograms (median: 0.1 microgram). CP and IF were found not only in the urine of pharmacy technicians and nurses actively handling these compounds (n = 2) but also in the urine of pharmacy technicians and nurses not directly involved in the preparation and administration of these two drugs (n = 6). CP and IF were excreted during different periods ranging from 1.40 to 24.15h after the beginning of the working day, suggesting different times of exposure, different exposure routes, and/or interindividual differences in biotransformation and excretion rate for these compounds.(ABSTRACT TRUNCATED AT 250 WORDS)