Mercury sphygmomanometers: disposal has far reaching consequences

Editor—The papers by O'Brien and Beevers et al have documented the trend away from the use of the mercury sphygmomanometer.¹,² But the ethical, legal, economic, and public health consequences associated with their disposal have not been so well documented. This lack of advice is surprising since mercury has well known toxic properties. Haphazard disposal of mercury inevitably leads to environmental recycling and bioconcentration, with ecological damage at best and human poisoning at worst.³

The Special Waste Regulations 1996 classify mercury and waste material containing more than 3% mercury as special waste and require extensive documented control of, and the use of approved contractors for, each stage of the disposal process. Non-compliance can result in a major fine, together with a custodial sentence.

Although technically only the mercury component is special, it would not be safe for staff to break sphygmomanometers open to access the mercury in uncontrolled conditions. In addition, we considered it likely that standard mercury containing sphygmomanometers used in general practice in England and Wales would contain more than 3% mercury and should therefore be considered special waste. We obtained four intact mercury sphygmomanometers from a general practitioner's surgery and drained and weighed the mercury under laboratory conditions. Each contained more than 3% mercury (average 6.5%).

The NHS must develop a policy for the storage and ultimate disposal of retired mercury sphygmomanometers that accords with the Special Waste Regulations 1996. Data from Birmingham health authority show that more than 30 000 mercury sphygmomanometers are still in active use by general practitioners in the UK. If plans are not made to dispose of these sphygmomanometers safely, some 1800 kg of mercury could enter the environment. The contamination that would result from the haphazard disposal of all mercury sphygmomanometers used in the NHS would be much greater, and the volumes involved suggest that collection and recycling may be commercially viable.

What should general practitioners, hospitals, and other NHS trusts do? Expecting each to negotiate a suitable system of collection and disposal would be burdensome, inefficient, and impractical, although it is their legal responsibility to do so. We are working with the environment agency in our region to develop an approved scheme that will reduce the bureaucratic demands on individual practices while protecting them from statutory action and, at the same time, provide a safe, efficient, and cost effective storage, transport, and disposal service.