Comment-21642-Larry Leroy Ladd

At the Aerojet Superfund Site in Rancho Cordova in 1998 we established a 4 ppt nitrosodimethylamine drinking water limit that has served us well as a risk driver for other unmonitored, unregulated chemicals associated with the breakdown products of unsymmetrical dimethyl hydrazine liquid rocket fuel like tetramethyl tetrazene, dimethyl formamide, acetylaldehyde, formaldehyde, etc. In particular, the formation of nitrosodimethylamine from chloramination of dimethyl formamide is a concern. The establishment of that 4 ppt standard was prompted by a female cancer cluster statistically significant to the 99th percentile (111 cases when the expectation was 85) in the census tract that encompassed the NDMA detections associated with a 1961 liquid rocket fuel spill. On the groundwater remediation frontier for that plume we monitor for ailments involving G12D and Q61R mutations of RAS and neural tube defects. When Arden Cordova water responded to your previous 100 ppt NDMA public health goal by turning on the 8 ppt NDMA tainted well at Peter J. Shields Elementary School, within 6 months two female juvenile cancer diagnoses prompted that well to be added to Aerojet's groundwater remediation system instead of drinking water. The first cancer in sight of the well was a fatal embryonal undifferentiated sarcoma of the liver in a 12 year old. This is a tumor where exposure to cytomegalovirus in the womb leaves the child vulnerable to KRAS mutation via altering microRNAs https://pmc.ncbi.nlm.nih.gov/articles/PMC7192511/. The second cancer case was a myeloid leukemia https://www.kcra.com/article/cordova-high-school-student-with-cancer-surprised-with-color-guard-performance/6250218 I have not been able to ascertain whether it was of a form associated with KRAS G12D mutation like monocytic leukemia, transition from chronic to acute juvenile myeloid leukemia, or early precursor T-cell lymphoma/leukemia. Because of the association between female Wilms tumor in the first edition of Mack's Cancers in the Urban Environment and historic liquid rocket fuel operations in El Monte, Van Nuys, and Santa Clarita I wrote Dr Andrew Jackson Murphy at Saint Judes about the pattern and in his subsequent paper linked here https://www.stjude.org/media-resources/news-releases/2019-medicine-science-news/models-wilms-tumor-research.html case 45 with its dearth of identified carcinogenic mutation (and presumed dominance of epigenetic carcinogenicity) seems to be a health outcome we try to avoid at our Superfund site. I tell my local elected officials that such a tumor in the context of neighboring subclinical neural tube defects like spina bifida occulta would be indicative to exposure to nitrosodimethylamine and other liquid rocket fuel breakdown products.