Joanne Colt

National Cancer Institute (USA), Bethesda, MD, USA

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Publications (11)53.74 Total impact

  • Source
    Article: Estimating water supply arsenic levels in the New England Bladder Cancer Study.
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    ABSTRACT: Ingestion of inorganic arsenic in drinking water is recognized as a cause of bladder cancer when levels are relatively high (≥ 150 µg/L). The epidemiologic evidence is less clear at the low-to-moderate concentrations typically observed in the United States. Accurate retrospective exposure assessment over a long time period is a major challenge in conducting epidemiologic studies of environmental factors and diseases with long latency, such as cancer. We estimated arsenic concentrations in the water supplies of 2,611 participants in a population-based case-control study in northern New England. Estimates covered the lifetimes of most study participants and were based on a combination of arsenic measurements at the homes of the participants and statistical modeling of arsenic concentrations in the water supply of both past and current homes. We assigned a residential water supply arsenic concentration for 165,138 (95%) of the total 173,361 lifetime exposure years (EYs) and a workplace water supply arsenic level for 85,195 EYs (86% of reported occupational years). Three methods accounted for 93% of the residential estimates of arsenic concentration: direct measurement of water samples (27%; median, 0.3 µg/L; range, 0.1-11.5), statistical models of water utility measurement data (49%; median, 0.4 µg/L; range, 0.3-3.3), and statistical models of arsenic concentrations in wells using aquifers in New England (17%; median, 1.6 µg/L; range, 0.6-22.4). We used a different validation procedure for each of the three methods, and found our estimated levels to be comparable with available measured concentrations. This methodology allowed us to calculate potential drinking water exposure over long periods.
    Environmental Health Perspectives 03/2011; 119(9):1279-85. · 7.04 Impact Factor
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    Article: Determinants of agricultural pesticide concentrations in carpet dust.
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    ABSTRACT: Residential proximity to agricultural pesticide applications has been used as a surrogate for exposure in epidemiologic studies, although little is known about the relationship with levels of pesticides in homes. We identified determinants of concentrations of agricultural pesticides in dust. We collected samples of carpet dust and mapped crops within 1,250 m of 89 residences in California. We measured concentrations of seven pesticides used extensively in agriculture (carbaryl, chlorpyrifos, chlorthal-dimethyl, diazinon, iprodione, phosmet, and simazine). We estimated use of agricultural pesticides near residences from a statewide database alone and by linking the database with crop maps. We calculated the density of pesticide use within 500 and 1,250 m of residences for 180, 365, and 730 days before collection of dust and evaluated relationships between agricultural pesticide use estimates and pesticide concentrations in carpet dust. For five of the seven pesticides evaluated, residences with use of agricultural pesticides within 1,250 m during the previous 365 days had significantly higher concentrations of pesticides than did residences with no nearby use. The highest correlation with concentrations of pesticides was generally for use reported within 1,250 m of the residence and 730 days before sample collection. Regression models that also accounted for occupational and home use of pesticides explained only a modest amount of the variability in pesticide concentrations (4-28%). Agricultural pesticide use near residences was a significant determinant of concentrations of pesticides in carpet dust for five of seven pesticides evaluated.
    Environmental Health Perspectives 02/2011; 119(7):970-6. · 7.04 Impact Factor
  • Article: Occupation and Bladder Cancer in a Population-Based Case-Control Study in Northern New England
    Epidemiology 10/2009; 20(6):S128. · 5.57 Impact Factor
  • Article: Occupation/industry and risk of non-Hodgkin's lymphoma in the United States.
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    ABSTRACT: To identify occupations and industries associated with non-Hodgkin's lymphoma (NHL) in a large population-based, case-control study in the USA. Cases (n = 1189) of histologically confirmed malignant NHL ages 20-74 were prospectively identified in four geographic areas covered by the National Cancer Institute SEER Program. Controls (n = 982) were selected from the general population by random digit dialling (<65 years of age) and from residents listed in Medicare files (65-74 years of age). Odds ratios and 95% confidence intervals for occupations and industries were calculated by unconditional logistic regression analyses, adjusting for age, gender, ethnicity and study centre. Further analyses stratified for gender and histological subtype were also performed. Risk of NHL was increased for a few occupations and industries. Several white collar occupations, with no obvious hazardous exposures, had elevated risks, including purchasing agents and buyers, religious workers, physical therapists and information clerks. Occupations with excesses that may have exposures of interest include launderers and ironers, service occupations, food/beverage preparation supervisors, hand packers and packagers, roofing and siding, leather and leather products, transportation by air, nursing and personal care facilities, and specialty outpatient clinics. Significantly decreased risks of NHL were found for a number of occupations and industries including post-secondary teachers and chemical and allied products. The results of this study suggest that several occupations and industries may alter the risk of NHL. Our results support previously reported increased risks among farmers, printers, medical professionals, electronic workers and leather workers. These findings should be evaluated further in larger studies that have the power to focus on specific exposures and histological subtypes of NHL.
    Occupational and environmental medicine 09/2008; 66(1):23-31. · 3.64 Impact Factor
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    Article: Census and geographic differences between respondents and nonrespondents in a case-control study of non-Hodgkin lymphoma.
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    ABSTRACT: To quantify nonresponse bias and estimate its potential impact, the authors compared census-based socioeconomic and demographic factors and geographic locations among respondents and nonrespondents in a multicenter case-control study of non-Hodgkin lymphoma (1998-2000). Using a geographic information system, the authors mapped current addresses and linked them to the 2000 US Census database to determine group-level demographic and socioeconomic information. They used logistic regression analysis to compute the risk of being a nonrespondent, separately for cases and controls. They used spatial scan methods to evaluate spatial clustering at each study center. Among cases at one or more centers, nonresponse was significantly associated with non-White race, lower household income, a greater proportion of multiple-unit housing, fewer years of education, and living in a more urbanized area. For most factors, the authors observed similar patterns among controls, although findings were mostly nonsignificant. They found two nonrandom elliptical clusters in Los Angeles, California, and Detroit, Michigan, that disappeared after adjustment for the demographic factors. The authors determined the bias in non-Hodgkin lymphoma risk associated with census-tract educational level by comparing risks among respondents and all subjects. The bias was 8%, indicating that the socioeconomic and demographic differences between respondents and nonrespondents did not result in a large bias in the risk estimate for education.
    American journal of epidemiology 03/2008; 167(3):350-61. · 5.59 Impact Factor
  • Article: Household vacuum cleaners vs. the high-volume surface sampler for collection of carpet dust samples in epidemiologic studies of children
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    ABSTRACT: Abstract Background Levels of pesticides and other compounds in carpet dust can be useful indicators of exposure in epidemiologic studies, particularly for young children who are in frequent contact with carpets. The high-volume surface sampler (HVS3) is often used to collect dust samples in the room in which the child had spent the most time. This method can be expensive and cumbersome, and it has been suggested that an easier method would be to remove dust that had already been collected with the household vacuum cleaner. However, the household vacuum integrates exposures over multiple rooms, some of which are not relevant to the child's exposure, and differences in vacuuming equipment and practices could affect the chemical concentration data. Here, we compare levels of pesticides and other compounds in dust from household vacuums to that collected using the HVS3. Methods Both methods were used in 45 homes in California. HVS3 samples were collected in one room, while the household vacuum had typically been used throughout the home. The samples were analyzed for 64 organic compounds, including pesticides, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls (PCBs), using GC/MS in multiple ion monitoring mode; and for nine metals using conventional microwave-assisted acid digestion combined with ICP/MS. Results The methods agreed in detecting the presence of the compounds 77% to 100% of the time (median 95%). For compounds with less than 100% agreement, neither method was consistently more sensitive than the other. Median concentrations were similar for most analytes, and Spearman correlation coefficients were 0.60 or higher except for allethrin (0.15) and malathion (0.24), which were detected infrequently, and benzo(k)fluoranthene (0.55), benzo(a)pyrene (0.55), PCB 105 (0.54), PCB 118 (0.54), and PCB 138 (0.58). Assuming that the HVS3 method is the "gold standard," the extent to which the household vacuum cleaner method yields relative risk estimates closer to unity by increasing random measurement error varies by compound and depends on the method used to calculate relative risk. Conclusion The household vacuum cleaner method appears to be a reasonable alternative to the HVS3 for detecting, ranking, and quantifying the concentrations of pesticides and other compounds in carpet dust.
    Environmental Health: A Global Access Science Source. 01/2008;
  • Article: Cellular telephones and non-Hodgkin lymphoma.
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    ABSTRACT: Dramatic increase in hand-held cellular telephone use since the 1980s and excess risk of lymphoproliferative malignancies associated with radio-frequency radiation (RFR) exposures in epidemiological and experimental studies motivated assessment of cellular telephones within a comprehensive US case-control investigation of non-Hodgkin lymphoma (NHL). A questionnaire ascertained cellular telephone use in 551 NHL cases and 462 frequency-matched population controls. Compared to persons who had never used cellular telephones, risks were not increased among individuals whose lifetime use was fewer than 10 (odds ratio (OR) = 0.9, 95% confidence intervals (CI): 0.6, 1.3), 10-100 (OR = 1.0, 95 % CI: 0.7, 1.5) or more than 100 times (e.g., regular users, OR = 0.9, 95% CI: 0.6, 1.4). Among regular users compared to those who had never used hand-held cellular telephones, risks of NHL were not significantly associated with minutes per week, duration, cumulative lifetime or year of first use, although NHL was non-significantly higher in men who used cellular telephones for more than 8 years. Little evidence linked use of cellular telephones with total, diffuse large B-cell lymphoma or follicular NHL. These findings must be interpreted in the context of less than 5% of the population reporting duration of use of 6 or more years or lifetime cumulative use of 200 or more hours.
    International Journal of Cancer 12/2006; 119(10):2382-8. · 5.44 Impact Factor
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    Article: Vegetables, fruit, and antioxidant-related nutrients and risk of non-Hodgkin lymphoma: a National Cancer Institute-Surveillance, Epidemiology, and End Results population-based case-control study.
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    ABSTRACT: Factors related to DNA damage and altered immunologic responses, such as reactive oxygen species production, are associated with the risk of non-Hodgkin lymphoma (NHL). The aim was to evaluate NHL risk with intakes of vegetables, fruit, and nutrients involved in antioxidant activities. Incident case subjects aged 20-74 y were identified between 1998 and 2000 from a National Cancer Institute-sponsored study by using four Surveillance, Epidemiology, and End Results registries. Control subjects, who were selected by random dialing (< 65 y) and from Medicare files (> or = 65 y), were matched to cases by age, center, race, and sex. Of 1321 case and 1057 control subjects who enrolled, dietary data were collected on a subset (466 cases and 391 controls). Carotenoid intakes were estimated by using updated values from the US Department of Agriculture nutrient databases. Unconditional logistic regression models were used to estimate odds ratios (ORs) and 95% CIs. NHL risk was inversely associated with higher number of weekly servings of all vegetables (multivariable OR for highest compared with lowest quartile: 0.58; 95% CI: 0.35, 0.95; P for trend = 0.04), green leafy vegetables (OR: 0.59; 95% CI: 0.36, 0.96; P for trend = 0.01), and cruciferous vegetables (OR: 0.62; 95% CI: 0.39, 1.00; P for trend = 0.05) and with higher daily intakes of lutein and zeaxanthin (OR: 0.54; 95% CI: 0.32, 0.91; P for trend = 0.06) and zinc (OR: 0.58; 95% CI: 0.36, 0.91; P for trend = 0.02). An effect modification by exercise and NHL subtype was observed with some food groups and nutrients. Higher intakes of vegetables, lutein and zeaxanthin, and zinc are associated with a lower NHL risk.
    American Journal of Clinical Nutrition 07/2006; 83(6):1401-10. · 6.67 Impact Factor
  • Article: Bladder cancer mortality and private well use in New England: an ecological study.
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    ABSTRACT: To investigate the possible relation between bladder cancer mortality among white men and women and private water use in New England, USA, where rates have been persistently raised and use of private water supplies (wells) common. Ecological study relating age adjusted cancer mortality rates for white men and women during 1985-1999 and proportion of persons using private water supplies in 1970. After regressing mortality rates on population density, Pearson correlation coefficients were computed between residual rates and the proportion of the population using private water supplies, using the state economic area as the unit of calculation. Calculations were conducted within each of 10 US regions. The 504 state economic areas of the contiguous United States. Mortality analysis of 11 cancer sites, with the focus on bladder cancer. After adjusting for the effect of population density, there was a statistically significant positive correlation between residual bladder cancer mortality rates and private water supply use among both men and women in New England (men, r = 0.42; women, r = 0.48) and New York/New Jersey (men, r = 0.49; women, r = 0.62). Use of well water from private sources, or a close correlate, may be an explanatory variable for the excess bladder cancer mortality in New England. Analytical studies are underway to clarify the relation between suspected water contaminants, particularly arsenic, and raised bladder cancer rates in northern New England.
    Journal of Epidemiology &amp Community Health 03/2006; 60(2):168-72. · 3.19 Impact Factor
  • Article: TP53 alterations and patterns of carcinogen exposure in a U.S. population-based study of bladder cancer.
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    ABSTRACT: The molecular pathology of bladder cancer has been the subject of considerable interest, and current efforts are targeted toward elucidating the interrelationships between individual somatic gene loss and both etiologic and prognostic factors. Mutation of the TP53 gene has been associated with more invasive bladder cancer, and evidence suggests that TP53 mutation, independent of stage, may be predictive of outcome in this disease. However, there is no consensus in the literature that bladder carcinogen exposure is associated with inactivation of the TP53 gene. Work to date has been primarily hospital based and, as such, subject to possible bias associated with selection of more advanced cases for study. We examined exposure relationships with both TP53 gene mutation and TP53 protein alterations in a population-based study of 330 bladder cancer cases in New Hampshire. Tobacco smoking was not associated with TP53 alterations. We found a higher prevalence of TP53 inactivation (i.e., mutation and nuclear accumulation) among hair dye users (odd ratio [OR] = 4.1; 95% confidence interval [CI] 1.2-14.7), and the majority of these mutations were transversions. Men who had "at risk" occupations were more likely to have mutated TP53 tumors (OR = 2.9; 95% CI 1.1-7.6). There also was a relative absence of TP53 mutation (OR = 0.4; 95% CI 0.0-2.9) and TP53 protein alterations (OR = 0.6; 95% CI 0.3-1.4) in bladder cancers from individuals with higher arsenic exposure. Our data suggest that there is exposure-specific heterogeneity in inactivation of the TP53 pathway in bladder cancers and that integration of the spectrum of pathway alterations in population-based approaches (capturing the full range of exposures to bladder carcinogens) may provide important insights into bladder tumorigenesis.
    International Journal of Cancer 12/2005; 117(3):370-5. · 5.44 Impact Factor
  • Article: Risk of non-Hodgkin's lymphoma and family history of lymphatic, hematologic, and other cancers.
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    ABSTRACT: An elevated risk of developing non-Hodgkin's lymphoma (NHL) has been associated with a family history of NHL and several other malignancies, but the magnitude of risks and mechanisms are uncertain. We used self-reported family history data from a recent multicenter U.S.-based case-control studies of NHL to evaluate familial aggregation of NHL with various hematolymphoproliferative and other cancers. Estimates of familial aggregation were obtained as hazard ratios (HR) that compare incidence of different cancers in first-degree relatives of NHL cases with that in the first-degree relatives of NHL controls. Limitations of the study included low participation rates (76% for cases and 52% for controls) and potential differential accuracy of recall. Risk of NHL was elevated in relatives of NHL cases [HR, 2.9; 95% confidence interval (95% CI), 0.95-8.53]; the aggregation seems to be stronger for siblings (HR, 7.6; 95% CI, 0.98-58.8) and for male relatives (HR, 6.2; 95% CI, 0.77-50.0). Risk of Hodgkin's lymphoma seems to be also elevated among relatives of early-onset (<50 years) NHL cases (HR, 3.2; 95% CI, 0.88-11.6). Evaluation of family history of other cancers provided modest evidence for an increased risk of melanoma of the skin (HR, 2.9; 95% CI, 1.08-7.75), pancreatic cancer (HR, 2.1; 95% CI, 0.96-4.43), stomach cancer (HR, 1.8; 95% CI, 0.91-3.63), and prostate cancer (HR, 1.3; 95% CI, 0.87-1.99). These results are consistent with previous findings of familial aggregation of NHL, Hodgkin's lymphoma, and a few other cancers. The pattern of male-specific and sibling-specific familial aggregation of NHL we observed, if confirmed, may shed new light on the possible mechanisms that underlie familial aggregation of the disease.
    Cancer Epidemiology Biomarkers &amp Prevention 10/2004; 13(9):1415-21. · 4.12 Impact Factor