Tosihiro Oka

Ranking the risks of 12 major environmental pollutants that occur in Japan.

The risks posed by 12 major environmental pollutants in Japan were evaluated and ranked on the same scale. These were arsenic, benzene, cadmium, chlordane, chlorpyrifos, DDTs, dioxins, formaldehyde, methylmercury, radon, toluene, and xylenes. Approximately half of these substances are carcinogenic while the other half are non-carcinogenic. We applied a risk estimation framework that can evaluate both cancer and non-cancer risks on the same scale. The framework consists of two parts: the calculation of the probability of adverse health effects, and the evaluation of the severity of the effects. In order to calculate the probability of adverse health effects, individual variabilities in exposure level, metabolizing rate, and sensitivity were taken into account. Loss of life expectancy (LLE; days) was used as a measure of severity of the adverse health effects and of the resulting risk level. The risk level of the substances in terms of LLE ranged from approximately 0.01 to 10 days. The risks from radon and formaldehyde were found to be the highest, while those from DDT and chlordane were the lowest. Our findings also suggested that the risk levels posed by non-carcinogenic substances were comparable to those posed by carcinogenic substances.

Was the risk from nursing-home evacuation after the Fukushima accident higher than the radiation risk?

After the 2011 accident at the Fukushima Daiichi nuclear power plant, nursing-home residents and staff were evacuated voluntarily from damaged areas to avoid radiation exposure. Unfortunately, the evacuation resulted in increased mortalities among nursing home residents. We assessed the risk trade-off between evacuation and radiation for 191 residents and 184 staff at three nursing homes by using the same detriment indicator, namely loss of life expectancy (LLE), under four scenarios, i.e. “rapid evacuation (in accordance with the actual situation; i.e. evacuation on 22 March),” “deliberate evacuation (i.e. evacuation on 20 June),” “20-mSv exposure,” and “100-mSv exposure.” The LLE from evacuation-related mortality among nursing home residents was assessed with survival probability data from nursing homes in the city of Minamisoma and the city of Soma. The LLE from radiation mortality was calculated from the estimated age-specific mortality rates from leukemia and all solid cancers based on the additional effective doses and the survival probabilities. The total LLE of residents due to evacuation-related risks in rapid evacuation was 11,000 persons-d—much higher than the total LLEs of residents and staff due to radiation in the other scenarios (27, 1100, and 5800 persons-d for deliberate evacuation, 20 mSv-exposure, and 100 mSv-exposure, respectively). The latitude for reducing evacuation risks among nursing home residents is surprisingly large. Evacuation regulation and planning should therefore be well balanced with the trade-offs against radiation risks. This is the first quantitative assessment of the risk trade-off between radiation exposure and evacuation after a nuclear power plant accident.

Calculating Cost‐Effectiveness for Activities with Multiple Environmental Effects Using the Maximum Abatement Cost Method

A maximum abatement cost (MAC) method is proposed as a means of assessing preferential purchasing of products with multiple environmental effects. Using the MAC method, cost‐effectiveness of the introduction of a product with less emissions of some substances than conventional products can be assessed. In the MAC method, the reduction of a pollutant is multiplied by the MAC, the maximum unit cost of the measures taken elsewhere in society aiming to reduce the pollutant, and is added up over the relevant pollutants. The total sum, called avoidable abatement cost (AAC), is compared with the additional private cost of the product for the purchaser. When the additional private cost is smaller than the AAC, the product is regarded as relatively eco‐efficient. The MAC method is illustrated with an assessment of industrial pumps. The advantages and limitations of the method are discussed.

The cost-effectiveness of life-saving interventions in Japan. Do chemical regulations cost too much?

This paper compares the cost-effectiveness of life-saving interventions in Japan, based on information collected from the health, safety and environmental literature. More than 50 life-saving interventions are analyzed. Cost-effectiveness is defined as the cost per life-year saved or as the cost per quality-adjusted life-year saved. Finding a large cost-effectiveness disparity between chemical controls and health care intervention, we raise the question of whether chemical regulations cost society too much. We point out the limitations of this study and propose a way to improve the incorporation of morbidity effects in cost-effectiveness analysis.

The Relation Between Value and Demand in the New Theory of International Values

The principal theorem of the new theory of international values for a Ricardo-Sraffa trade economy is presented and then illustrated using a two-country, two-commodity model and a two-country, three-commodity model. It is shown that the classical vision of values as independent of demand is preserved, even when international trade takes place. In other words, values are mainly determined by costs of production or, ultimately, by technology. The values are, however, not determined uniquely, and demand plays a role in selecting a set of values from among those that are admissible under present technology and mark-up rates. Three different production possibility frontiers are introduced: R-efficient locus, physical maximal frontier and capitalistically feasible frontier. It is argued that distinguishing among these three frontiers is necessary in order to comprehend the role of demand in determining international value. Lastly, the similarity of this relation of value and demand to that of rent theory is pointed out.

The New Theory of International Values in the Context of the Ricardo-Sraffian Theory of Value and Distribution

In this article we introduce readers to the new theory of international values by placing it in the context of the Ricardo-Sraffian theory of value and distribution. Ricardo’s theory is described as that in which exchangeable values of commodities are regulated by the quantities of labour bestowed in their production, on which he established his theory on the distribution of the produce of the earth. Contemporary classical theory, founded by Sraffa, is described as preserving Ricardo’s perspective of the value independent of distribution and of demand by replacing the labour theory with the production-cost theory. After noting that Ricardo left the question of determination of values of the commodities traded internationally, it is shown that J. S. Mill argued that the law of demand and supply determines them, which conflicts with the classical perspective. We then demonstrate how the new theory of international values solves the question in line with the classical vision. Lastly, the similarity between this theory and Sraffa’s treatment of multiple products is indicated.