Already, public vigilance and inspections have lapsed as the threat of cholera fades from memory. However, annual benefits could range from one third to almost all of the cost of treatment, with the wide range resulting from different assumptions about the probability of a cholera epidemic occurring under current conditions. These numbers greatly understate the true benefits, because they do not include the health costs of other gastroenteric diseases such as hepatitis and diarrhea, the amenity values of improved coastal water quality, the impact on fish and shellfish production, or the value of water-use rights for Santiago's treated effluents. Nor does the study consider the impact of future outbreaks of cholera or typhoid on the growth of fruit exports or on tourism. Industrial boilers account for more than half of SOx emissions, with vehicles accounting for another one fourth.
Particulates are by far the most serious pollutant.
The study then developed a dispersion model to simulate the strategy's impact on air quality, particularly in heavily populated and highly polluted areas. Because these estimates are considered conservative, it is likely that substantially larger investments would also be cost- effective. For example, the health valuation accounts only for lost productivity and treatment costs, while the estimate of health effects considers only acute effects and not cumulative and long-term effects. References and Notes 1.