2012年-世界发展银行全球_Transport_Emissions_and_Savings_in_Health_Costs_56页_2mb

Summary of Transport Emissions and Savings in Health Costs

Core Content

This document is part of a World Bank/DFID initiative titled "Transport Emissions and Savings in Health Costs." It aims to develop an estimation approach to quantify the health impacts of transport-related air pollution and translate these into health cost savings, providing a basis for ex-ante policy assessments in developing countries.

The report focuses on the relationship between transport emissions, air quality, and health outcomes in urban areas. It outlines the methodology for calculating health impacts and their economic value, emphasizing the need for context-specific analysis and the challenges of applying findings from developed countries to developing ones.

Main Objectives

• To estimate how health impacts of transport can be transferred to different contexts.
• To identify the key determinants linking transport services to health costs.
• To establish an estimation equation that relates these determinants to health costs across various urban environments.

Key Areas of Focus

1. Health Impacts of Transport-Related Air Pollution

Transport emissions, especially particulate matter (PM), nitrogen oxides (NOx), and sulfur dioxide (SO₂), are strongly associated with a range of health conditions, including:

• Cardiovascular Diseases: Increased risk of heart attacks, stroke, and other cardiovascular issues.
• Respiratory Diseases: Asthma, chronic bronchitis, reduced lung function, and acute respiratory symptoms.
• Cancer: Particularly lung cancer, and possibly other types like breast and ovarian cancer.
• Other Effects: Fertility issues, adverse pregnancy outcomes, and reduced quality of life.

2. Health Impact Calculation Methodology

The report explains the process of calculating health impacts using a four-step approach:

1. Scoping Choices: Define the health endpoints and pollutants of interest.
2. Population Exposed: Identify the population at risk based on exposure levels and susceptibility.
3. Calculate Health Impacts: Use dose-response functions (DRFs) to estimate the health risks associated with pollutant exposure.
4. Monetise Health Impacts: Apply valuation methods such as Willingness to Pay (WTP) or Cost of Illness (COI) to estimate health cost savings.

3. Valuation of Health Impacts

• Dose-Response Functions (DRFs): These are used to estimate the percentage increase in health risk per unit increase in pollutant concentration. DRFs are typically derived from epidemiological studies and can be linear or non-linear.
• Willingness to Pay (WTP): Used to estimate the economic value of health improvements. Country-specific WTP values are recommended due to variations in economic conditions and health priorities.
• Cost of Illness (COI): Another valuation method that quantifies the direct and indirect costs of health impacts.
• Benefit Transfer Approach (BTA): A method to apply existing DRFs and WTP values from one region to another, with caution due to potential differences in context.

4. Challenges and Considerations

• Methodological Challenges: Uncertainty remains in the accurate quantification and valuation of health impacts due to data limitations and differences in local conditions.
• Local Conditions in Developing Countries: These include higher pollution levels, lack of regulatory frameworks, and different demographic and socioeconomic profiles.
• Confounding Factors: Include age, gender, SES, and geographical location, which influence the health impact of pollution.
• Dose-Response Complexity: Health effects are often due to a mix of pollutants, making it difficult to isolate individual impacts.

Key Information

Recommended Values for Health Impacts

• PM10 and PM2.5: These are the most significant pollutants for health impacts.
• NOx and SO₂: Also contribute to health risks, particularly in the development of respiratory and cardiovascular diseases.
• WTP Values: Country-specific values are recommended, with examples from the WHO and Yaduma (2011) showing variations across regions.
• Health Endpoints: Include both short-term (e.g., daily mortality, acute symptoms) and long-term (e.g., chronic diseases, cancer) effects.

Example of the Four-Step Approach

The report provides an example of applying the four-step method in Beijing, highlighting the potential health benefits of reducing PM10 to WHO guideline levels, such as:

• Reduction in mortality.
• Decrease in chronic bronchitis cases.
• Fewer asthma attacks.
• Lower number of restricted activity days.

Conclusion

The report serves as a foundational step toward creating a tool for evaluating the health effects of transport emissions in developing countries. It emphasizes the need for context-specific analysis, the importance of understanding the causal links between emissions and health outcomes, and the challenges of applying global data to local settings. The ultimate goal is to support policy decisions by quantifying the health savings from reducing transport emissions.