# Particulate Air Pollution, Birth Outcomes, and Infant Mortality: Evidence from Japan's Automobile Emission Control Law of 1992

## TL;DR

This study assesses the 1992 Japanese automobile emission law's impact, showing significant reductions in pollutants and improvements in fetal health outcomes, highlighting the policy's positive effects on infant mortality and birth outcomes.

## Contribution

It provides the first empirical evidence linking Japan's 1992 automobile emission regulation to improved fetal health and reduced infant mortality.

## Key findings

- NOx and SO2 levels decreased significantly after regulation
- Fetal death rates improved notably post-regulation
- Automobile emission control positively affected infant health

## Abstract

This study investigates the impacts of the Automobile NOx Law of 1992 on ambient air pollutants and fetal and infant health outcomes in Japan. Using panel data taken from more than 1,500 monitoring stations between 1987 and 1997, we find that NOx and SO2 levels reduced by 87% and 52%, respectively in regulated areas following the 1992 regulation. In addition, using a municipal-level Vital Statistics panel dataset and adopting the regression differences-in-differences method, we find that the enactment of the regulation explained most of the improvements in the fetal death rate between 1991 and 1993. This study is the first to provide evidence on the positive impacts of this large-scale automobile regulation policy on fetal health.