The Public Health Record of Nyanza
What is the Ashland Nyanza Health Study?
In 1998, Kevin Kane reported to the MDPH that young adults, including himself, and others that had lived in the town and played on the Nyanza Chemical site as children had recently developed similar types of rare cancers.
The concern focused on a suspected cluster of five young men of similar age that developed various types of soft tissue sarcomas and the possibility that past exposure from the Nyanza Chemical Site may be causing an increase in cancer diagnoses among current and former Ashland residents.
The Ashland Nyanza Health Study is a retrospective cohort study which attempted to recreate the population of Ashland children between the ages 10 and 18 during the years 1965 to 1985. The study was conducted to determine whether cancer incidence among former Ashland residents is related to contact with the former Nyanza Chemical Dump.
A total of 1,387 individuals participated in the study, yielding a response rate of 67.5%. The mean age of study participants was 39.8 years. Seventy-three individuals reported a cancer diagnosis at the time of interview. These individuals comprise the case group.
The MDPH was able to medically confirm the diagnosis for 55% (N=40) of the 73 individuals who self-reported a cancer diagnosis. Thirty-four percent of the case group was diagnosed with a cancer type categorized as a rare cancer type.
Analyses were conducted with all individuals who self-reported a cancer diagnosis (N=73) as well as those individuals with a confirmed cancer diagnosis (N=40) and rare cancer (N=25).
Initial analyses involving the entire case group showed that three areas of the Nyanza site were associated with an increased risk of cancer. These areas included the Eastern Wetlands (Area B), the Sudbury River near High Street (Area F), and the Sudbury and Mill Pond area (Area G).
The associations were observed among study participants who reported any contact in these areas and a positive family history of cancer. When the analyses focused on specific types of activities at the Nyanza site that could potentially be associated with an increased risk of cancer, the study found that activities involving water contact at two areas of the site were associated with an increased risk of cancer.
These areas included Area D (Megunko Hill) and Area H (the Sudbury River near Myrtle Street). Study participants who reported activities related to any type of water contact, specifically swimming or wading, at these two areas showed a statistically significantly increased risk of cancer diagnoses. The increased risk of cancer was two to three times greater than the risk of cancer for study participants who reported no contact with these areas of the Nyanza site.
Further, for individuals who reported water contact in Areas D or H and a positive family history of cancer, the risk of cancer increased to nearly four times the risk of study participants who reported no family history of cancer. These results were statistically significant and were observed when the analyses included the entire case group of participants who self-reported a cancer diagnosis as well as those with a medically confirmed cancer diagnosis.
In addition, evaluation of specific locations depicted within the defined exposure areas of the Nyanza site showed statistically significant associations between overall water contact at Chemical Brook and the two waste lagoons located on Megunko Hill.
These results were statistically significant when the analyses included individuals who had a confirmed cancer diagnosis as the case group as well as only those individuals who had a rare cancer diagnosis. Again, the results were confirmed and remained statistically significant when a family history of cancer was considered in the analyses
LINK from the State’s Executive Office of Health and Human Services (EOHHS) (formerly referred to in earlier reports as DPH) on the entire report: