The health impacts associated with particulates and low-level ozone, and quantified on the basis of epidemiological evidence, ranges from minor respiratory conditions to cardio-pulmonary related mortality. CBA that includes these impacts is an established feature of air quality regulation formulation in North America and Europe. Indeed, reduced mortality impacts have dominated the benefits included in many recent appraisals of such policy development, though the robust valuation of these impacts is still evolving.
Heavy metals are associated with a variety of cancer impacts as well as on neurological development, renal dysfunction and a number of other impacts. These impacts are increasing being quantified and valued, in response to the requirement for more rigour arising from regulatory agencies in OECD countries. Increasingly sophisticated approaches to deal with the current attendant uncertainties are also being utilised.
The health risks from unsafe water and sanitation derive from faecal contamination, bacteria and viruses and include gastroenteritis, diarrhoea amongst others. OECD countries use of quantified information relating to these risks in CBA is currently in the context of wastewater management, where benefit-cost ratios are sometimes found to be less than one. In contrast, in developing countries, health risks are included in the appraisal of water supply investments. In these countries, health risks are significant but generally not as important as time savings in the benefits side of the CBA, though the quantification and monetisation of health risks is often rather partial.
