Excess leukemia and multiple myeloma in a mining county in northeast Texas

From 1950 to 1979, cancer mortality rates in Titus County, Texas, increased with a significant excess of deaths from leukemia, lymphoma, brain and liver cancers, and melanoma. County residents requested this study to verify the apparent excess of cancer. Newly diagnosed cases of cancer among white residents from 1977 to 1984 were ascertained from the Texas Cancer Registry, hospital records, and death certificates. Direct and indirect methods were used to calculate incidence rates and standardized incidence ratios (SIR). We identified 663 cancers for 148,470 person-years of observation. No overall excess of cancer was found. However, we found a significant excess of leukemia (SIR = 2.53, 95% confidence interval [CI] = 1.86, 3.30) and multiple myeloma (SIR = 1.87, 95% CI = 1.02, 3.14). The reasons for the increased SIRs are unknown. However, the excess of cancers in this mining community may be relevant to the ongoing debate on the health effects of the disposal of combustion wastes from mining and fossil fuel and on the need for stricter regulations. Other potential risk factors include the presence of petrochemical and poultry industries. regulations. Other potential risk factors include the presence of petrochemical and poultry industries.