Urban Heat Islands and It's Correlation to Neural Tube Defect Prevalence in the United States and United Kingdom

The Urban Heat Island effect is defined as an urban area having higher than average surface temperatures than its rural and non-urban surroundings. The infrastructure of urban settings causes the increased retention of heat, causing the heat island effect. This phenomenon will lead to an increase in heat related symptoms such as stroke, hyperthermia, heat exhaustion, and heat cramps. Research has further shown that excess heat can affect mothers who are pregnant and thus affect their infants’ growth through neural tube defects. Neural tube defects or NTDs are anomalies that occur when the neural tube does not close properly during its formation. The neural tube is responsible for forming the early brain and spine, and develops very early in pregnancy. The two most common NTDs are Spina Bifida (a spinal cord defect in which some of the vertebrae are not completely closed) and Anencephaly (a brain defect causing an open brain and lack of skull vault).

The first part of the project focused on showing a U.S. wide comparison between heat and the prevalence of NTDs. Spina Bifida and Anencephaly prevalence data per 100,000 live births for 5 year periods was acquired from the CDC EPH Tracking system. The data was then graphed to see the pattern and to capture any outlying states that had differing patterns of growth. This data was then compared to 2m temperature data from ERA5 for the same consecutive 5 periods of time to see any pattern between states with a higher average temperature and NTDs, and states with a higher average change in temperature and NTDs. There was no distinct pattern found between high temperatures or high changes in temperatures and NTDs. Neural tube defects also seemed to have no pattern throughout time, not increasing nor decreasing. The second part of the project focused on specific states and counties, going to a more urban scale. Arizona and California were determined to be “mixed” states with both high and low average temperatures, and two counties from each were selected and their NTD prevalence was compared against each other. One county was determined to have UHI qualities such as high average heat, high population, and highly developed imperviousness. Maricopa and Cocoino from Arizona were selected with Maricopa being the UHI representative. Fresno and San Luis Obispo from California were selected with Fresno being the UHI representative. Then, Arizona and California were compared as whole states. The same was done for “cold”/low average temperature and “hot”/high average temperature states Wyoming and Florida respectively. The conclusions proved to be inconclusive as most of the states and counties with lower average temperatures seemed to have higher prevalence of both NTDs. This could be due to inconsistencies in the NTD data provided by the CDC.

Therefore, the third part of the project was focused on NTD data found from the European Platform on Rare Disease that had more consistent recorded data from 1980 - 2021. NTD data from EPRD was compared to the 2m temperature data from ERA5 from the years 2000 - 2021. Then, more focused comparisons were made by focusing on highly populated urban areas in the north east (with higher average temperatures and change in temperature) and in the south of the UK (with lower average temperatures and change in temperature). The data from the US and UK was then compared to note any differences in the correlation between NTD prevalence and air temperature between the two regions.

Afterwards, the experiment was repeated for both US and UK urban regions using the same sources of NTD data but different ERA5 temperature data. The data in question is the Thermal Comfort Indices temperature data which takes into account wind, humidity, radiation, and other atmospheric conditions giving a more accurate reading on temperature experienced by people. This data was then compared to the data collected using ERA5 2m temperature data to note any significant differences.