Biological Safety Cabinets - Laminar Air flow: The Netherlands
Cytotoxic drugs are widely used in the treatment of cancer and some non-neoplastic diseases. This class of drugs exhibits a high degree of biological activity and acts primarily by interfering with the synthesis of DNA during the replication of tumor cells, resulting in a marked decrease in the replication of malignant cells. Cytotoxic drugs are highly non-selective in their activity, however, resulting in damage to normal (non tumor) cells during normal replication.
Toxic side effects
Patients treated with cytotoxic drugs commonly exhibit acute toxic side effects. The long term toxic side effects include mutagenic, carcinogenic, and reproductive changes.
The International Agency for Research on Cancer (IARC) has determined that a sufficient body of data exists to support the human carcinogenicity of nine (alkylating) cytotoxic drugs. Nurse handling alkylating cytotoxic drugs have also been found to be at increased risk for leukemia.
Some epidemiological studies suggest that increases in the number of spontaneous abortions and fetal malformations in the offspring of nurses working in environments where cytotoxic drugs are prepared or administered may be caused by occupational exposure to these agents. Another study illustrates some of the adverse acute and reproductive effects related to occupational exposure. Recently, infertility among nurses and pharmacists handling cytotoxic drugs was reported.
Occupational exposure and personal protection
Based on the present scientific knowledge of the mechanism of action of genotoxic carcinogens such as alkylating cytotoxic drugs, it is assumed that a no-adverse-effect level cannot safely be established. Occupational exposure to any level of these drugs should therefore be avoided.
Safety guidelines and protective measures have been implemented to protect health care workers when preparing, handling, and administering cytotoxic drugs.
In The Netherlands, the first monitoring studies regarding exposure to cytotoxic drugs were performed in the period 1982-1986.
The first guideline was introduced in 1986 containing a lot of information about the potential risks of cytotoxic drugs and suggestions how to reduce exposure.
In 1992, the second guideline was introduced. The results of several monitoring studies were used to improve preparation and administration techniques, cleaning procedures and personal protective measures. Measures taken were strongly focused on personal protection.
In 1997, the third guideline was presented. Monitoring studies did not show a substantial reduction of environmental contamination and exposure over the last years. It seems that the amount of personal protection – often regarded as overkill - has not improved the situation. Therefore, the third guideline focused on less personal protection and more to avoid contact with the drugs (reduction of sources of exposure). All preparations were centralized in the pharmacy. More attention was given to the administration of the drugs and handling of excreta. Environmental monitoring (wipe tests) was strongly recommended.
In 2001, wipe tests to evaluate environmental contamination became obliged.
In 2004, the fourth guidelines was introduced. Not really a guideline but a kind of an agreement between employers and employees (Arbo-convenant) about the control measures to be taken into the hospitals to reduce contamination and potential exposure (state of the art techniques, training and education). More attention for dermal exposure (use of gloves) and the patient as source of exposure (excreta).
In 2006, the Inspectorate of Labour has inspected 170 departments in the hospitals. One third of the departments was approved. Two third was not approved (mainly oncology and urology).
Results and conclusions
Although the number of preparations and administrations has increased over the last 20 years, this has not resulted in increased environmental contamination and exposure of health care workers. On the contrary, environmental contamination with and exposure to cytotoxic drugs has decreased. Results of some studies will be presented. In addition, monitoring has proven to be an effective tool to improve the safety of the health care workers regarding potential exposure to cytotoxic drugs.