Clay's research focuses on the health effects of air pollution and climate change. Much of her work on air pollution intersects with energy. For example, Clay's research examines pollution arising from the use of coal to generate electricity and the use of pipelines and railroads to move crude oil to refineries. Clay has given talks or participated in panels for the Pittsburgh Post Gazette, Heinz College, the Carnegie Mellon Scott Institute in Pittsburgh and in Washington DC.
In the News
Examines the impact of lead exposure on a critical human function with societal implications – fertility. Uses two sets of instruments: i) the interaction of the timing of implementation of Clean Air Act regulations and the 1944 Interstate Highway System Plan for the panel data and ii) the 1944 Interstate Highway System Plan for the cross sectional data. Finds that reductions in airborne lead between 1978 and 1988 increased fertility rates and that higher lead in topsoil decreased fertility rates in the 2000s.
Documents mortality in the United States for temperatures over 80F fell over 70% over the twentieth century and almost all of the decline occurred after 1960. Shows the decline is almost entirely explained by the expansion of air conditioning.
Presents evidence that cities with lead drinking water pipes had higher infant mortality in the early 20th century and that cities with lead pipes and more acidic water, which is associated with greater leaching of lead, had higher infant mortality than cities with lead pipes and less acidic water.
Shows that air pollution and spill and accident costs associated with moving crude oil are much higher (6.7x) for rail and for pipeline and that air pollution costs are much larger (9x) than spill and accident costs. Finds that the majority of the air pollution costs are from criteria pollutants and not carbon dioxide.
Documents mortality in the United States for temperatures over 80F fell 70% over the twentieth century and almost all of the decline occurred after 1960. Shows the decline is almost entirely explained by the expansion of air conditioning.
Highlights the extent of mid-twentieth century air pollution in the United States and provides estimates of health impacts of increased coal-fired electricity generation on infant mortality. Shows tradeoffs in health effects of increased coal-fired electricity generation for infants and in property values across locations with high and low levels of access to electricity.
Shows the impact of extreme heat on mortality is smaller in states that more frequently experience extreme heat and that the difference in the heat-mortality relationship between hot and cold states declined over 1900-2004 but had not disappeared as of 2004.