What about the environmental impact of other anaesthetic drugs?

If inhalational anaesthetic agents and nitrous oxide contribute to global warming, it might seem more sensible to abandon their use altogether and use other methods of anaesthesia. However, two factors should be borne in mind. Firstly, there is a climate cost involved in the manufacture and transport of these drugs. Secondly, anaesthetic drugs are metabolised and excreted by the body into the environment. There has been little research published in anaesthesia journals in this regard. Comprehensive research, however, has been reported by both Stockholm County Council and the US Environmental Protection Agency, who have rated a myriad of chemical compounds according to a sum value (‘PBT value’, out of 9) of their environmental persistence, potential for bioaccumulation and their toxicity (depending on the medium in which the chemicals are found):

Score

Persistence

Potential for bioaccumulation

Toxicity

0

Readily biodegradable

No

Low

1

 

 

Moderate

2

 

 

High

3

Not readily biodegradable

Yes

Very high

Examples of anaesthetic drugs

Drug

Risk

PBT

Persistence

Bioaccumulation

Toxicity

Propofol

Low

6

3

0

3

Fentanyl

Medium

7

3

3

1

Atracurium

Low

2

0

0

2

Bupivacaine

Low

5

3

0

2

The figures reported do not take into account biotransformation within the human body, which may alter PBT scores, and further research is required.