Showing papers by "Margaret R. Karagas published in 1999"

Increase in incidence rates of basal cell and squamous cell skin cancer in New Hampshire, USA

Abstract: We conducted a study to estimate the current incidence rates of basal-cell carcinoma (BCC) and squamous-cell carcinoma (SCC) of the skin in the population of New Hampshire (NH), USA, and to quantify recent changes in the incidence rates of these malignancies. BCCs and SCCs diagnosed among NH residents were identified through physician practices and central pathology laboratories in NH and bordering regions from June 1979 through May 1980 and from July 1993 through June 1994. For each diagnosis period, we estimated the age-adjusted incidence rates for both BCC and SCC among both men and women and for separate anatomic sites. Between 1979-1980 and 1993-1994, incidence rates of SCC increased by 235% in men and by 350% in women. Incidence rates of BCC increased by more than 80% in both men and women. While the absolute increase was greatest for tumors of the head and neck, the relative change was most pronounced for tumors on the trunk in men and on the lower limb in women. Thus, there has been a marked rise in the incidence rates of BCC and SCC skin cancers in NH in recent years. The anatomic pattern of increase in BCC and SCC incidence is consistent with an effect of greater sunlight exposure. Studies of BCC and SCC occurrence are needed to identify possible behavioral and environmental factors and to assess possible changes in diagnostic practices that might account for the rise in incidence of these common malignancies.

Design of an Epidemiologic Study of Drinking Water Arsenic Exposure and Skin and Bladder Cancer Risk in a U.S. Population

Abstract: Ingestion of arsenic-contaminated drinking water is associated with an increased risk of several cancers, including skin and bladder malignancies; but it is not yet clear whether such adverse effects are present at levels to which the U.S. population is exposed. In New Hampshire, detectable levels of arsenic have been reported in drinking water supplies throughout the state. Therefore, we have begun a population-based epidemiologic case-control study in which residents of New Hampshire diagnosed with primary squamous cell (n = 900) and basal cell (n = 1200) skin cancers are being selected from a special statewide skin cancer incidence survey; patients diagnosed with primary bladder cancers (n = 450) are being identified through the New Hampshire State Cancer Registry. Exposure histories of these patients will be compared to a control group of individuals randomly selected from population lists (n = 1200). Along with a detailed personal interview, arsenic and other trace elements are being measured in toenail clipping samples using instrumental neutron activation analysis. Household water samples are being tested on selected participants using a hydride generation technique with high-resolution inductively coupled plasma mass spectrometry. In the first 793 households tested arsenic concentrations ranged from undetectable (0.01 microgram/l) to 180 microgram/l. Over 10% of the private wells contained levels above 10 microgram/l and 2.5% were above 50 microgram/l. Based on our projected sample size, we expect at least 80% power to detect a 2-fold risk of basal cell or squamous cell skin cancer or bladder cancer among individuals with the highest 5% toenail concentrations of arsenic.

Arsenic Occurrence in New Hampshire Drinking Water

Abstract: Arsenic concentrations were measured in 992 drinking water samples collected from New Hampshire households using online hydride generation ICP-MS. These randomly selected household water samples contain much less arsenic than those voluntarily submitted for analysis to the New Hampshire Department of Environmental Services (NHDES). Extrapolation of the voluntarily submitted sample set to all New Hampshire residents significantly overestimates arsenic exposure. In randomly selected households, concentrations ranged from <0.0003 to 180 μg/L, with water from domestic wells containing significantly more arsenic than water from municipal sources. Water samples from drilled bedrock wells had the highest arsenic concentrations, while samples from surficial wells had the lowest arsenic concentrations. We suggest that much of the groundwater arsenic in New Hampshire is derived from weathering of bedrock materials and not from anthropogenic contamination. The spatial distribution of elevated arsenic concentrations ...