Environmental Public Health Commons^™

Neighborhood Environment And Falls Among Community-Dwelling Older Adults, Emily Nicklett, Matthew Lohman, Matthew Smith

Dartmouth Scholarship

Falls present a major challenge to active aging, but the relationship between neighborhood factors and falls is poorly understood. This study examined the relationship between fall events and neighborhood factors, including neighborhood social cohesion (sense of belonging, trust, friendliness, and helpfulness) and physical environment (vandalism/graffiti, rubbish, vacant/deserted houses, and perceived safety walking home at night).

A Multiscale Mapping Assessment Of Lake Champlain Cyanobacterial Harmful Algal Blooms, Nathan Torbick, Megan Corbiere, Yu-Pin Lin

Dartmouth Scholarship

Lake Champlain has bays undergoing chronic cyanobacterial harmful algal blooms that pose a public health threat. Monitoring and assessment tools need to be developed to support risk decision making and to gain a thorough understanding of bloom scales and intensities. In this research application, Landsat 8 Operational Land Imager (OLI), Rapid Eye, and Proba Compact High Resolution Imaging Spectrometer (CHRIS) images were obtained while a corresponding field campaign collected in situ measurements of water quality. Models including empirical band ratio regressions were applied to map chlorophylla and phycocyanin concentrations; all sensors performed well with R² and root-mean-square error (RMSE) ranging …

Isolation Of Mycobacterium Avium From Potable Water In Homes And Institutions Of Patients With Hiv Infection In Finland And The United States, Matti Ristola, Robert D. Arbeit, C. Fordham Von Reyn, C. Robert Horsburgh

Dartmouth Scholarship

Symptomatic disease by nontuberculous mycobacteria has been linked to potable water from institutional and domestic potable water systems. Potable water samples were collected from homes and institutions of patients with AIDS. Colonization of potable water with nontuberculous mycobacteria was demonstrated in 230 (15%) of 1489 samples collected from domestic and institutional water systems of patients with HIV infection in the United States and Finland. Mycobacterium avium was the most common species and colonization was favored at temperatures of 40–50°C in recirculating hot water systems. Such systems are a plausible source of human infection and disease.

Influence Of Environmental Exposure On Human Epigenetic Regulation, C. J. Marsit

Dartmouth Scholarship

Environmental toxicants can alter epigenetic regulatory features such as DNA methylation and microRNA expression. As the sensitivity of epigenomic regulatory features may be greatest during the in utero period, when critical windows are narrow, and when epigenomic profiles are being set, this review will highlight research focused on that period. I will focus on work in human populations, where the impact of environmental toxicants in utero, including cigarette smoke and toxic trace metals such as arsenic, mercury and manganese, on genome-wide, gene-specific DNA methylation has been assessed. In particular, arsenic is highlighted, as this metalloid has been the focus …

A Dietary-Wide Association Study (Dwas) Of Environmental Metal Exposure In Us Children And Adults, Matthew A. Davis, Diane Gilbert-Diamond, Margaret R. Karagas, Zhigang Li, Jason H. Moore, Scott M. Williams, H. Robert Frost

Dartmouth Scholarship

Background: A growing body of evidence suggests that exposure to toxic metals occurs through diet but few studies have comprehensively examined dietary sources of exposure in US populations.

Purpose: Our goal was to perform a novel dietary-wide association study (DWAS) to identify specific dietary sources of lead, cadmium, mercury, and arsenic exposure in US children and adults.

Methods: We combined data from the National Health and Nutrition Examination Survey with data from the US Department of Agriculture’s Food Intakes Converted to Retail Commodities Database to examine associations between 49 different foods and environmental metal exposure. Using blood and urinary biomarkers …

Relationship Between Altitude And Lithium In Groundwater In The United States Of America: Results Of A 1992–2003 Study, Rebekah S. Huber, Namkug Kim, Carl E. Renshaw, Perry F. Renshaw, Douglas Kondo

Dartmouth Scholarship

Therapeutic dosages of lithium are known to reduce suicide rates, which has led to investigations of confounding environmental risk factors for suicide such as lithium in groundwater. It has been speculated that this might play a role in the potential relationship between suicide and altitude. A recent study in Austria involving geospatial analysis of lithium in groundwater and suicide found lower levels of lithium at higher altitudes. Since there is no reason to suspect this correlation is universal given variation in geology, the current study set out to investigate the relationship between altitude and lithium in groundwater in the United …

Association Between In Utero Arsenic Exposure, Placental Gene Expression, And Infant Birth Weight: A Us Birth Cohort Study, Dennis Liang Fei, Devin C. Koestler, Zhigang Li, Camilla Giambelli, Avencia Sanchez-Mejias, Julie Gosse, Carmen J. Marsit, Margaret R. Karagas, David J. Robbins

Dartmouth Scholarship

Epidemiologic studies and animal models suggest that in utero arsenic exposure affects fetal health, with a negative association between maternal arsenic ingestion and infant birth weight often observed. However, the molecular mechanisms for this association remain elusive. In the present study, we aimed to increase our understanding of the impact of low-dose arsenic exposure on fetal health by identifying possible arsenic-associated fetal tissue biomarkers in a cohort of pregnant women exposed to arsenic at low levels.

Methods: Arsenic concentrations were determined from the urine samples of a cohort of 133 pregnant women from New Hampshire. Placental tissue samples collected from …

Diet And Toenail Arsenic Concentrations In A New Hampshire Population With Arsenic-Containing Water, Kathryn L. Cottingham, Roxanne Karimi, Joann F. Gruber, M Scot Zens, Vicki Sayarath, Carol L. Folt, Tracy Punshon, J. Steven Morris, Margaret R. Karagas

Dartmouth Scholarship

Background: Limited data exist on the contribution of dietary sources of arsenic to an individual's total exposure, particularly in populations with exposure via drinking water. Here, the association between diet and toenail arsenic concentrations (a long-term biomarker of exposure) was evaluated for individuals with measured household tap water arsenic. Foods known to be high in arsenic, including rice and seafood, were of particular interest.

Methods: Associations between toenail arsenic and consumption of 120 individual diet items were quantified using general linear models that also accounted for household tap water arsenic and potentially confounding factors (e.g., age, caloric intake, sex, smoking) …

Associations Between Cadmium Exposure And Neurocognitive Test Scores In A Cross-Sectional Study Of Us Adults, Timothy Ciesielski, David C. Bellinger, Joel Schwartz, Russ Hauser, Robert O. Wright

Dartmouth Scholarship

Background: Low-level environmental cadmium exposure and neurotoxicity has not been well studied in adults. Our goal was to evaluate associations between neurocognitive exam scores and a biomarker of cumulative cadmium exposure among adults in the Third National Health and Nutrition Examination Survey (NHANES III).

Methods: NHANES III is a nationally representative cross-sectional survey of the U.S. population conducted between 1988 and 1994. We analyzed data from a subset of participants, age 20–59, who participated in a computer-based neurocognitive evaluation. There were four outcome measures: the Simple Reaction Time Test (SRTT: visual motor speed), the Symbol Digit Substitution Test (SDST: attention/perception), …

Associations Between Toenail Arsenic Concentration And Dietary Factors In A New Hampshire Ppopulation, Joann F. Gruber, Margaret R. Karagas, Diane Gilbert-Diamond, Pamela J. Bagley, M Scot Zens, Vicki Sayarath, Tracy Punshon, J Steven Morris, Kathryn L. Cottingham

Dartmouth Scholarship

Background: Dietary factors such as folate, vitamin B12, protein, and methionine are important for the excretion of arsenic via one-carbon metabolism in undernourished populations exposed to high levels of arsenic via drinking water. However, the effects of dietary factors on toenail arsenic concentrations in well-nourished populations exposed to relatively low levels of water arsenic are unknown.

Methods: As part of a population-based case-control study of skin and bladder cancer from the USA, we evaluated relationships between consumption of dietary factors and arsenic concentrations in toenail clippings. Consumption of each dietary factor was determined from a validated food frequency questionnaire. We …

Two Boundaries Separate Borrelia Burgdorferi Populations In North America, Gabriele Margos, Jean I. Tsao, Santiago Castillo-Ramirez, Yvette A. Girard, Anne G. Hoen

Dartmouth Scholarship

Understanding the spread of infectious diseases is crucial for implementing effective control measures. For this, it is important to obtain information on the contemporary population structure of a disease agent and to infer the evolutionary processes that may have shaped it. Here, we investigate on a continental scale the population structure of Borrelia burgdorferi, the causative agent of Lyme borreliosis (LB), a tick-borne disease, in North America. We test the hypothesis that the observed d population structure is congruent with recent population expansions and that these were preceded by bottlenecks mostly likely caused by the near extirpation in the 1900s …

Rice Consumption Contributes To Arsenic Exposure In Us Women, Diane Gilbert-Diamond, Kathryn L. Cottingham, Joann F. Gruber, Tracy Punshon, Vicki Sayarath, A. Jay Gandolfi, Emily R. Baker, Brian P. Jackson, Carol L. Folt, Margaret R. Karagas

Dartmouth Scholarship

Emerging data indicate that rice consumption may lead to potentially harmful arsenic exposure. However, few human data are available, and virtually none exist for vulnerable periods such as pregnancy. Here we document a positive association between rice consumption and urinary arsenic excretion, a biomarker of recent arsenic exposure, in 229 pregnant women. At a 6-mo prenatal visit, we collected a urine sample and 3-d dietary record for water, fish/seafood, and rice. We also tested women's home tap water for arsenic, which we combined with tap water consumption to estimate arsenic exposure through water. Women who reported rice intake (n …

Oral Ingestion Of Hexavalent Chromium Through Drinking Water And Cancer Mortality In An Industrial Area Of Greece - An Ecological Study, Athena Linos, Athanassios Petralias, Costas A. Christophi, Eleni Christoforidou, Paraskevi Kouroutou, Melina Stoltidis, Afroditi Veloudaki, Evangelia Tzala, Konstantinos C. Makris, Margaret R. Karagas

Dartmouth Scholarship

Background: Hexavalent chromium is a known carcinogen when inhaled, but its carcinogenic potential when orally ingested remains controversial. Water contaminated with hexavalent chromium is a worldwide problem, making this a question of significant public health importance.

Methods: We conducted an ecological mortality study within the Oinofita region of Greece, where water has been contaminated with hexavalent chromium. We calculated gender, age, and period standardized mortality ratios (SMRs) for all deaths, cancer deaths, and specific cancer types of Oinofita residents over an 11-year period (1999 - 2009), using the greater prefecture of Voiotia as the standard population.

Results: A total of …

Urogenital Abnormalities In Men Exposed To Diethylstilbestrol In Utero: A Cohort Study, Julie R. Palmer, Arthur L. Herbst, Kenneth L. Noller, Deborah A. Boggs, Rebecca Troisi, Linda Titus-Ernstoff, Elizabeth E. Hatch, Lauren A. Wise, William C. Strohsnitter, Robert N. Hoover

Dartmouth Scholarship

Background: Diethylstilbestrol (DES), a synthetic estrogen widely prescribed to pregnant women during the 1940s70s, has been shown to cause reproductive problems in the daughters. Studies of prenatally-exposed males have yielded conflicting results.

Methods: In data from a collaborative follow-up of three U.S. cohorts of DES-exposed sons, we examined the relation of prenatal DES exposure to occurrence of male urogenital abnormalities. Exposure status was determined through review of prenatal records. Mailed questionnaires (1994, 1997, 2001) asked about specified abnormalities of the urogenital tract. Risk ratios (RR) were estimated by Cox regression with constant time at risk and control for year of …

Reduction In Urinary Arsenic With Bottled-Water Intervention, Arun B. Josyula, Hannah Mcclellen, Tracy A. Hysong, Margaret Kurzius-Spencer, Gerald S. Poplin, Stefan Stürup, Jefferey L. Burgess

Dartmouth Scholarship

The study was conducted to measure the effectiveness of providing bottled water in reducing arsenic exposure. Urine, tap-water and toenail samples were collected from non-smoking adults residing in Ajo (n=40) and Tucson (n=33), Arizona, USA. The Ajo subjects were provided bottled water for 12 months prior to re-sampling. The mean total arsenic (microg/L) in tap-water was 20.3+/-3.7 in Ajo and 4.0+/-2.3 in Tucson. Baseline urinary total inorganic arsenic (microg/L) was significantly higher among the Ajo subjects (n=40, 29.1+/-20.4) than among the Tucson subjects (n=32, 11.0+/-12.0, p<0.001), as was creatinine-adjusted urinary total inorganic arsenic (microg/g) (35.5+/-25.2 vs 13.2+/-9.3, p<0.001). Baseline concentrations of arsenic (microg/g) in toenails were also higher among the Ajo subjects (0.51+/-0.72) than among the Tucson subjects (0.17+/-0.21) (p<0.001). After the intervention, the mean urinary total inorganic arsenic in Ajo (n=36) dropped by 21%, from 29.4+/-21.1 to 23.2+/-23.2 (p=0.026). The creatinine-adjusted urinary total inorganic arsenic and toenail arsenic levels did not differ significantly with the intervention. Provision of arsenic-free bottled water resulted in a modest reduction in urinary total inorganic arsenic.

Chemopreventive Effect Of Oltipraz On Afb1-Induced Hepatocarcinogenesis In Tree Shrew Model, Yuan Li, Jian Jia Su, Liu L. Qin, Chun Yang, Dan Luo, Ke C. Ban, T. W. Kensler, B. D. Roebuck

Dartmouth Scholarship

Hepatocellular carcinoma (HCC) is one of the major cancers in the world with a mortality of more than 250 000 cases yearly. More than 137 000 cases of HCC were diagnosed each year in China, which acount approximately for more than 40 percent of the total number in the world. HCC has become the second major cause of death for cancer in China since 1990, and its annual mortality is expected to be 21.2 cases per 100 000 population in the year 2000. Even though progresses have been achieved for HCC diagnosis and treat ment, its 5-year mortality is still …

Journey In A Forgotten Land- Part 2: Food And Drought: The Broader Picture, Norman Miller

Dartmouth Scholarship

Kenya and Ethiopia handled the drought very differently, both in action and public statements. Ethiopian officials in the south spoke openly and candidly about famine and starvation and willingly gave access to mortality statistics. They also bitterly criticized the former regime for its inept attempt to deal with the famine. Kenya's administrators were cautious and guarded; they denied that any great suffering had occurred and sought to avoid publicity. Missionaries in northern Kenya were advised to give aid without fanfare, not to write home about the famine, and to keep conditions confidential.