Over the weekend, we analyzed another 72 lead samples collected by Flint residents and mailed to Virginia Tech. For the 120 samples analyzed to date, forty two percent were over 5 ppb, which suggests a serious lead in water problem according to our experience and criteria.
Twenty-three (20% of the 120 samples collected to date) also exceeded the 15 ppb lead action limit. The highest lead sampled in first draw so far was 158 ppb, and the highest sample after 45 second flushing is 1,051 ppb. Six of 120 homes sampled (5%), had over 15 ppb lead even after 2 minutes of continuous flushing.
The 90%’ile lead level in the Flint Water Study is currently 30 ppb, which is double the EPA standard applied to homes with “worst case” lead plumbing, and in a range where water consumption has caused lead poisoning in children and adverse pregnancy outcomes. Needless to say, these data are very worrisome, especially considering that our survey did not target “worst case” lead plumbing systems as is required for EPA sampling.
Look at our summary page here for more details. We just heard that we are approaching the 250 (out of 300) mark of returned kits and we couldn’t be more grateful and proud of Flint’s citizen scientists. Please continue collecting samples, as larger number of samples helps to draw stronger conclusions. More samples may also help Flint residents understand what regions of the city and the types of plumbing systems that have the most serious lead problems. We are also contacting homes with high lead levels via phone and email and all sampled residents will receive their results via regular mail.
Our team (including Anurag Mantha, not pictured) hard at work towards analyzing the 72 lead kits (216 samples) over the weekend
Primary Author: Dr. Marc Edwards
Acknowledgements: William Rhoads, Siddhartha Roy