Research

Putting data science to work on major research projects

We have participated in more than two dozen major research efforts including several large studies funded by the US National Institutes of Health and US Environmental Protection Agency. In the context of these studies we have authored or co-authored more than 60 research papers.

Publications

  1. 2024

    • Filippelli GM, Dietrich M, Shukle J, Wood L, Margenot A, Egendorf SP, Mielke HW. One in Four US Households Likely Exceed New Soil Lead Guidance Levels. GeoHealth, June 2024, Volume 8, Issue 6. Available here.
    • Ananth CV, Lee R, Valeri L, Ross Z, Graham H, Khan S, Cabrera J, Rosen T, Kostis W. Placental Abruption and Cardiovascular Event Risk (PACER): Design, data linkage, and preliminary findungs. Paediatric and Perinatal Epidemiology, January 2024. Available here.
  2. 2022

    • Kirkby K, Schlotheuber A, Fuertes CV, Ross Z, Hosseinpoor, AR. Health Equity Assessment Toolkit (HEAT and HEATPlus): exporting inequalities in the COVID-19 pandemic era. International Journal for Equity in Health, December 2022. Available here.
    • Mielnik A, Martenies SE, Heiderscheidt JM, Su J, Ross Z, Jerrett M, Balmes JR, Magzamen S. Location-weighted traffic-related air pollution and asthma symptoms in urban adolescents. Air Quality, Atmosphere & Health, March 2022. Available here.
    • Wang Y, Perera F, Guo J, Riley KW, Durham T, Ross Z, Ananth CV, Baccarelli A, Wang S, Herbstman J. A methodological pipeline to generate an epigenetic marker of prenatal exposure to air pollution indicators. Epigenetics, January 2022, volume 17, issue 1, 32:40. Available here.
  3. 2021

    • Linton S, DesJarlais DC, Ornstein JT, Kasman M, Hammond R, Kianian B, Smith JC, Wolfe M, Ross Z, Germana D, Flynn C, Raymond HF, Klevens RM, Spencer E, Schacht J-M, Finlayson T, Paz-Bailey G, Wejnert C, Cooper HLM. An Application of Agent-Based Modeling to Explore the Impact of Decreasing Incarceration Rates and Increasing Drug Treatment Access on Sero-Discordant Partnerships Among People Who Inject Drugs. International Journal of Drug Policy, volume 94, August 2021, 103194. Available here.
    • Martenies SE, Keller JP, WeMott S, Kuiper G, Ross Z, Allshouse WB, Adgate JL, Starling AP, Dabelea D, and Magzamen S. A Spatiotemporal Prediction Model for Black Carbon in the Denver Metropolitan Area, 2009–2020. Environmental Science & Technology, February 2021. Available here.
    • Wang Y, Perera F, Guo J, Riley KW, Durham T, Ross Z, Ananth CV, Baccarelli A, Wang S, and Herbstman JB. A Methodological Pipeline to Generate an Epigenetic Marker of Prenatal Exposure to Air Pollution Indicators. Epigenetics, January 2021. Available here.
    • Huang Y, Kioumourtzoglou M, Mittleman M, Ross Z, Williams M, Friedman A, Schwartz J, Wapner R and Ananth C. Air Pollution and Risk of Placental Abruption: A Study of Births in New York City, 2008-2014. American Journal of Epidemiology, kwaa2559. Available here.
    • Perera F, Berberian, A, Cooley D, Shenaut E, Olmstead H, Ross Z, and Matte T. Potential Health Benefits of Sustained Air Quality Improvements in New York City: A Simulation Based on Air Pollution Levels During the COVID-19 Shutdown. Environmental Research, volume 193, February 2021. Available here.
  4. 2020

    • Johnson S, Ross Z, Kheirbek I, and Ito K. Characterization of Intra-Urban Spatial Variation in Observed Summer Ambient Temperature from the New York City Community Air Survey. Urban Climate, volume 31, March 2020, 100583. Available here.
    • Ananth C, Kioumourtzoglou M, Huang Y, Ross Z, Friedman AM, Williams MA, Mittleman MA, Schwartz J, Wapner, RJ. Air Pollution and Risk of Placental Abruption: A Study of Births in New York City, 2008-2014. American Journal of Epidemiology.
  5. 2019

    • Des Jarlais DC, McKnight C, Arasteh K, Feelemyer J, Ross Z and Cooper HLF. Geographic Distribution of Risk (“Hotspots”) for HIV, HCV and Drug Overdose Among Persons Who Use Drugs in New York City: the Importance of Local History. Harm Reduction Journal, December 2019, volume 16 (1), 53. Available here.
    • Nayak SG, Shrestha S, Sheridan SC, Hsu WH, Muscatiello NA, Pantea CI, Ross Z, Kinney PL, Zdeb M, Hwang SA and Lin S. Accessibility of Cooling Centers to Heat-Vulnerable Populations in New York State. Journal of Transport & Health, volume 14, September 2019, 100563. Available here.
    • Tempalski B, Cooper HLF, Kelley ME, Linton SL, Wolfe ME, Chen YT, Ross Z, Des Jarlais DC, Friedman SR, Williams LD, Semaan S, DiNenno E, Wejnert C, Broz D, Paz-Bailey G and National HIV Behavioral Surveillance Study Group. Identifying Which Place Characteristics are Associated with the Odds of Recent HIV Testing in a Large Sample of People who Inject Drugs in 19 US Metropolitan Areas. AIDS and Behavior, February 2019, volume 23, issue 2, 318:335. Available here.
  6. 2018

    • Hosseinpoor AR, Schlotheuber A, Nambiar D and Ross Z. Health Equity Assessment Toolkit Plus (HEAT Plus): software for exploring and comparing health inequalities using uploaded datasets. Global Health Action 11 (Supplement 1). Available here.
    • Tempalski B, Cooper HLF, Kelley ME, Linton SL, Wolfe ME, Chen Y-T, Ross Z, Des Jarlais DC, Friedman SR, Williams LD, Semaan S, DiNenno E, Wejnert C, Broz D, Paz-Bailey G, for the National HIV Behavioral Surveillance Study Group. Identifying Which Place Characteristics are Associated with the Odds of Recent HIV Testing in a Large Sample of People Who Inject Drugs in 19 US Metropolitan Areas. AIDS and Behavior, 1-18. Available here.
    • Ananth C, Kioumourtzoglou M, Huang Y, Ross Z, Friedman AM, Williams MA, Wang S, Mittleman MA, Schwartz J. Exposures to Air Pollution and Risk of Acute-Onset Placental Abruption: A Case-Crossover Study. Epidemiology 29 (5), 631-638.
    • Haley DF, Wingood GM, Kramer MR, Haardörfer R, Adimora AA, Rubtsova A, Edmonds A, Goswami ND, Ludema C, Hickson DA, Ramirez C, Ross Z, Bolivar H, Cooper HLF. Associations Between Neighborhood Characteristics, Social Cohesion, and Perceived Sex Partner Risk and Non-Monogamy Among HIV-Seropositive and HIV-Seronegative Women in the Southern U.S. Archives of Sexual Behavior, 1-13. Available here.
    • Nayak SG, Shrestha S, Kinney PL, Ross Z, Sheridan SC, Pantea CI, Hsu WH, Muscatiello N, Hwang SA. Development of a Heat Vulnerability Index for New York State. Public Health 161: 127-137. Available here.
    • Des Jarlais DC, Cooper HLF, Arasteh K, Feelemyer J, McKnight C, Ross Z. Potential Geographic “Hotspots” for Drug-Injection Related Transmission of HIV and HCV and for Initiation into Injecting Drug Use in New York City, 2011-2015, with Implications for the Current Opioid Epidemic in the US. PLOS One 13(3), e0194799. Available here.
  7. 2017

    • Ross Z, Wickham H, Robinson D. 2017. Declutter your R workflow with tidy tools. Practical Data Science for Stats - a PeerJ Collection. Available here.
    • Haley DF, Haardörfer R, Kramer MR, Adimora AA, Wingood GM, Goswami ND, Rubtsova A, Ludema C, Hickson DA, Ramirez C, Ross Z, Bolivar H, Cooper HLF. Associations between Neighborhood Characteristics and Sexual Risk Behaviors among HIV-infected and HIV-uninfected Women in the Southern United States. Annals of Epidemiology 27(4): 252-259. Available here.
    • Haley DF, Kramer MR, Adimora AA, Haardörfer R, Wingood GM, Ludema C, Rubtsova A, Hickson DA, Ross Z, Golub E, Bolivar H, Cooper HLF. Relationships between Neighbourhood Characteristics and Current STI Status among HIV-Infected and HIV-Uninfected Women Living in the Southern USA: a Cross-Sectional Multilevel Analysis. Sexually Transmitted Infections, 2016-052889. Available here.
    • Linton SL, Haley DF, Hunter-Jones J, Ross Z Cooper HLF. Social Causation and Neighborhood Selection Underlie Associations of Neighborhood Factors with Illicit Drug-Using Social Networks and Illicit Drug Use Among Adults Relocated from Public Housing. Social Science & Medicine 185: 81-90. Available here.
    • Haley DF, Linton S, Luo R, Hunter-Jones J, Adimora AA, Wingood GM, Bonney L, Ross Z, Cooper HLF. Public Housing Relocations and Relationships of Changes in Neighborhood Disadvantage and Transportation Access to Unmet Need for Medical Care. Journal of Health Care for the Poor and Underserved 28(1): 315-328. Available here.
    • Linton SL, Cooper HLF, Kelley ME, Karnes CC, Ross Z, Wolfe ME, Friedman SR, Des Jarlais D, Semaan S, Tempalski B, Sionean C, DiNenno E, Wejnert C, Paz-Bailey G, for the National HIV Behavioral Surveillance Study Group. Cross-Sectional Between ZIP Code-Level Gentrification and Homelessness Among a Large Community-Based Sample of People Who Inject Drugs in 19 US Cities. BMJ Open 7 (6): e013823. Available here.
    • Linton SL, Cooper, HLF, Luo R, Karnes C, Renneker K, Haley DF, Dauria EF, Hunter-Jones J, Ross Z, Wingood GM, Adimora AA, Bonney L, Rothenberg R. Change Places and Partners: Associations of Neighborhood Conditions with Sexual Network Turnover Amoung African American Adults relocated from Public Housing. Archives of Sexual Behavior 46 (4): 925-936. Available here.
  8. 2016

    • Hosseinpoor AR, Nambiar D, Schlotheuber A, Reidpath D, Ross Z. 2016. Health Equity Assessment Toolkit (HEAT): Software for exploring and comparing health inequalities in countries. BMC Medical Research Methodology. 16:141.
    • Ito K, Johnson S, Kheirbek I, Clougherty J, Pezeshki G, Ross Z, Eisl H, Matte T. Intra-urban variation of fine particle elemental concentrations in New York City. Environmental Science & Technology 50(14): 7517–7526.
    • Johnson S, Bobb JF, Ito K, Savitz DA, Elston B, Shmool J, Dominici F, Ross Z, Clougherty JE, Matte T. Ambient fine particulate matter, nitrogen dioxide, and preterm birth in New York City. Environmental Health Perspectives 124: 1283–1290.
    • Cooper HLF, Linton S, Kelley ME, Ross Z, Wolfe ME, Chen Y-T, Zlotorzynska M, Hunter-Jones J, Friedman SR, Des Jarlais DC, Tempalski B, DiNenno E, Broz D, Wejnert C, Paz-Bailey G. For the National HIV Behavioral Surveillance Study Group. Risk environments, race/ethnicity, and HIV status in a large sample of people who inject drugs in the United States. PLOS One 11(3).
    • Linton SL, Cooper HLF, Luo R, Karnes CC, Renneker K, Haley DF, Dauria EF, Hunter-Jones J, Ross Z, Wingood G, Adimora AA, Bonney L, Rothenberg R. Changing places and partners: longitudinal associations of neighborhood conditions with sexual network turnover among African American adults relocated from public housing in Atlanta, Georgia**. **Archives of Sexual Behavior**. In press.
    • Cooper HLF, Bonney L, Luo R, Haley DF, Linton S, Hunter-Jones J, Ross Z, Wingood GM, Adimora AA, Rothenberg R. Public Housing Relocations and Partnership Dynamics in Areas with High Prevalences of Sexually Transmitted Infections. Sexually Transmitted Diseases 43(4).
    • Cooper HLF, Linton S, Kelley ME, Ross Z, Wolfe ME, Chen Y, Zlotorzynska M, Hunter-Jones J, Friedman SR, Des Jarlais D, Semaan S, Tempalski B, DiNenno E, Broz D, Wejnert C, Paz-Bailey G, National HIV Behavioral Surveillance Study Group. Racialized risk environments in a large sample of people who inject drugs in the United States. International Journal of Drug Policy 27:43-55.
    • Linton SL, Cooper HLF, Luo R, Karnes C, Renneker K, Haley DF, Dauria EF, Hunter-Jones J, Ross Z, Wingwood GM, Adimora AA, Bonney L, Rothenberg R. Changing Places and Partners: Associations of Neighborhood Conditions With Sexual Network Turnover Among African American Adults Relocated From Public Housing. Archives of Sexual Behavior. ePub: 1-12.
  9. 2015

    • Loving Carr Shmool J, Bobb JF, Ito K, Savitz DA, Elston B, Ross Z, Matte TD, Johnson S, Dominici F, Clougherty JE. Area-level socioeconomic deprivation, nitrogen dioxide exposure, and term birth weight in New York City. Environmental Research. 142:624-632.
    • Linton S, Cooper HLF, Kelley ME, Karnes CC, Ross Z, Wolfe ME, Friedman SR, Des Jarlais D, Semaan S, Tempalski B, Finlayson T, Sionean C, DiNenno E, Wejnert C, Paz-Bailey G, for the National HIV Behavioral Surveillance Study Group. HIV Infection Among People Who Inject Drugs in the United States: Geographically Explained Variance Across Racial and Ethnic Groups. American Journal of Public Health. 105(12):2457-2465.
    • Savitz DA, Elston B, Bobb JF, Clougherty JE, Dominici F, Ito K, Johnson S, McAlexander T, Ross Z, Shmool JL, Matte TD, Wellenius GA. 2015. Ambient fine particulate matter, nitrogen dioxide, and hypertensive disorders of pregnancy in New York City. Epidemiology 26(5):748-757.
    • Ito K, Weinberger KR, Robinson GS, Sheffield PE, Lall R, Mathes R, Ross Z, Kinney PL, Matte TD. 2015. The associations between daily spring pollen counts, over-the-counter allergy medication sales, and asthma syndrome emergency department visits in New York City, 2002-2012. Environmental Health. 14:71.
    • Cooper HLF, Linton S, Haley DF, Kelley ME, Dauria EF, Karnes CC, Ross Z, Hunter-Jones J, Renneker KK, del Rio C, Adimora A, Wingood GM, Rothenberg RR, Bonney LE. 2015. Changing Exposure to Neighborhood Characteristics Are Associated with Sexual Network Characteristics in a Cohort of Adults Relocating from Public Housing. AIDS and Behavior 19(6): 1016-30.
    • Linton SL, Cooper HLF, Luo R, Karnes CC, Renneker K, Haley DF, Hunter-Jones J, Ross Z, Bonney L, Rothenberg R. People and places: relocating to neighborhoods with better economic and social conditions is associated with less risky drug/alcohol network characteristics among African American adults in Atlanta, GA. Drug and Alcohol Dependence 160:30-41.
  10. 2014

    • Lee E, Jerrett M, Ross Z, Coogan P, Seto E. 2014. Assessment of Traffic-Related Noise in Three Cities in the United States. Environmental Research 132: 182-89.
    • Savitz DA, Bobb J, Carr JL, Clougherty JE, Dominici F, Elston B, Ito K, Ross Z, Yee M, Matte TD. 2014. Ambient Fine Particulate Matter, Nitrogen Dioxide, and Term Birth Weight in New York, New York. American Journal of Epidemiology 179(4): 457-66.
    • Kheirbek I, Ito K, Neitzel R, Kim J, Johnson S, Ross Z, Eisl H, Matte T. 2014. Spatial Variation in Environmental Noise and Air Pollution in New York City. Journal of Urban Health 91(3): 415-31.
    • Cooper HL, Hunter-Jones J, Kelley ME, Karnes C, Haley D, Ross Z, Rothenberg R, Bonney LE. 2014. The Aftermath of Public Housing Relocations: Relationships between Changes in Local Socioeconomic Conditions and Depressive Symptoms in a Cohort of Adult Relocaters. Journal of Urban Health 91(2): 223-41.
    • Cooper HLF, Haley DF, Linton S, Hunter-Jones J, Martin M, Kelley ME, Karnes CC, Ross Z, Adimora AA, del Rio C, Rothenberg R., Wingood GM, Bonney LE. 2014. Impact of Public Housing Relocations: Are changes in neighborhood conditions related to STIs among relocaters? Sexually Transmitted Diseases 41(10).
  11. 2013

    • Ross Z, Ito K, Johnson S, Yee M, Pezeshki G, Clougherty JE, Savitz D, Matte T. 2013. Spatial and temporal estimation of air pollutants in New York City: exposure assignment for use in a birth outcomes study. Environmental Health 12(51): 1-13.
    • Cooper HL, Bonney LE, Ross Z, Karnes C, Hunter-Jones J, Kelley M; Rothenberg R. 2013. The Aftermath of Public Housing Relocation: Relationship to Substance Misuse Drug and Alcohol Dependence. Drug and Alcohol Dependence 133(1): 37-44.
    • Beckerman B, Jerrett, M, Serre M, Martin R, Lee S, van Donkelaar A, Ross Z, Su J, Burnett R. 2013. A Hybrid Approach to Estimating National Scale Spatiotemporal Variability of PM2.5 in the Contiguous United States. **Environmental Science & Technology **47(13): 7233–7241.
    • Matte TD, Ross Z, Kheirbek I, Eisl H, Johnson J, Gorczynski JE, Kass D, Markowitz S, Pezeshki G, Clougherty JE. 2013. Monitoring intra-urban spatial patterns of multiple combustion air pollutants in New York City: Design and implementation. Journal of Exposure Science and Environmental Epidemiology 23: 223–231.
    • Clougherty JE , Kheirbek I, Eisl H, Ross Z, Pezeshki G, Gorczynski JE, Johnson S, Markowitz S, Kass D, Matte TD. 2013. Intra-urban spatial variability in wintertime street-level concentrations of multiple combustion-related air pollutants: The New York City Community Air Survey (NYCCAS). Journal of Exposure Science and Environmental Epidemiology 23: 232-240.
    • Beckerman B, Jerrett M, Martin RV, van Donkelaar A, Ross Z, Burnett R. 2013. Application of the deletion/substitution/addition algorithm to selecting land use regression models for interpolating air pollution measurements in California. Atmospheric Environment 77: 172-177.
    • Ito K, Ross Z, Zhou J, Nadas A, Lippman M, Thurston GD. 2013. NPACT Study 3. Time-Series Analysis of Mortality, Hospitalizations, and Ambient PM2.5 and Its Components. In: National Particle Component Toxicity (NPACT) Initiative: Integrated Epidemiologic and Toxicologic Studies of the Health Effects of Particulate Matter Components. Research Report 177. Health Effects Institute, Boston, MA.
  12. 2012

    • Cooper HLF, Wodarski S, Cummings J, Hunter-Jones J, Karnes C, Ross Z, Druss B, Bonney LE. 2012. Public housing relocations in Atlanta, Georgia, and declines in spatial access to safety net primary care. Health & Place 18: 1255–1260.
    • Kheirbek I, Johnson S, Ross Z, Pezeshki G, Ito K, Eisl H, Matte T. 2012. Spatial variability in levels of benzene, formaldehyde, and total benzene, toluene, ethylbenzene and xylenes in New York City: a land-use regression study. Environmental Health 11: 51.
    • Cooper HLF, Des Jarlais DC, Ross Z, Tempalski B, Bossak B, Friedman SR. 2012. Spatial access to sterile syringes and the odds of injecting with an unsterile syringe among injectors: a longitudinal multilevel study. Journal of Urban Health 89(4): 678-96.
    • Dlugacz YD, Fleischer A, Carney MT, Copperman N, Ahmed I, Ross Z, Buchman T, Fried AM, Cabello C, De Geronimo M, Sweetapple C, Besthoff CM, Silverman RA. 2012. 2009 H1N1 vaccination by pregnant women during the 2009-10 H1N1 influenza pandemic. American Journal of Obstetrics & Gynecology 206(4): 339.e1-8.
    • Cooper HLF, Des Jarlais DC, Tempalski B, Bossak BH, Ross Z, Friedman SR. 2012. Drug-Related Arrest Rates and Spatial Access to Syringe Exchange Programs in New York City Health Districts: Combined Effects on the Risk of Injection-Related Infections among Injectors. Health & Place 18(2): 218-228.
  13. 2011

    • Ross Z, Kheirbek I, Clougherty JE, Ito K, Matte T, Markowitz S, Eisl H. 2011. Noise, air pollutants and traffic: Continuous measurement and correlation at a high-traffic location in New York City. Environmental Research 111(8): 1054-1063.
    • Ito K, Mathes R, Ross Z, Nádas A, Thurston G, Matte T. 2011. Fine Particulate Matter Constituents Associated with Cardiovascular Hospitalizations and Mortality in New York City. Environmental Health Perspectives 119(4): 467-473.
    • Cooper H, Des Jarlais D, Ross Z, Tempalski B, Bossak B, Friedman S. 2011. Spatial Access to Syringe Exchange Programs and Pharmacies Selling Over-the-Counter Syringes as Predictors of Drug Injectors' Use of Sterile Syringes. American Journal of Public Health 101(6): 1118-1125.
  14. 2009

    • Krewski D, Jerrett M, Burnett RT, Ma R, Hughes E, Shi Y, Turner MC, Pope CA 3rd, Thurston G, Calle EE, Thun MJ, Beckerman B, DeLuca P, Finkelstein N, Ito K, Moore DK, Newbold KB, Ramsay T, Ross Z, Shin H, Tempalski B. 2009. Extended follow-up and spatial analysis of the American Cancer Society study linking particulate air pollution and mortality. Res Rep Health Eff Inst 140: 5-136.
    • English P, Sinclair A, Ross Z, Anderson H, Boothe V, Davis C, Ebi K, Kagey B, Malecki K, Shultz R, Simms E. 2009. Environmental Health Indicators of Climate Change for the United States: Findings from the State Environmental Health Indicator Collaborative. Environmental Health Perspectives 117(11): 1673-1681.
  15. 2007

    • Holguin F, Flores S, Ross Z, Cortez M, Molina M, Molina L, Rincon C, Jerrett M, Berhane K, Romieu I. 2007. Traffic-related exposures, airway inflammation and respiratory symptoms in children. American Journal of Respiratory and Critical Care Medicine 176: 1236-1242.
    • Ross Z, Ito K, Tempalski B, Thurston G, Jerrett M. 2007. A land use regression for predicting fine particulate matter concentrations in the New York City region. Atmospheric Environment 41: 2255-2269.
  16. 2006

    • Ross Z, Duxbury J, DeGloria S, Paul D. 2006. Potential for arsenic contamination of rice in Bangladesh: spatial analysis and mapping of high risk areas. International Journal of Risk Assessment and Management 6(6): 298-315.
    • Ross Z, English P, Scalf R, Gunier R, Smorodinsky S, Wall S, Jerrett M. 2006. Nitrogen dioxide prediction in Southern California using land use regression modeling: potential for environmental health analyses. Journal of Exposure Science and Environmental Epidemiology 16: 106-114.
    • Pfeffer M, Francis J, Ross Z. 2006. Fifty years of farmland change: Urbanization, population growth and the changing farm economy. In WA Kandel & DL Brown (eds.), Population Change and Rural Society: 103-129.
  17. Acknowledged Contributions

    • Springer YP, Samuel MC, Bolan G. 2010. Socioeconomic gradients in sexually transmitted diseases: a geographic information system-based analysis of poverty, race/ethnicity, and gonorrhea rates in California 2004-2006. American Journal of Public Health 100(6): 1060-1067.
    • Smith K, Jerrett M, Anderson H, Burnett R, Stone V, Derwent R, Atkinson R, Cohen A, Shonkoff S, Krewski D, Pope CA, Thun M, Thurston G. 2009. Public health benefits of strategies to reduce greenhouse-gas emissions: health implications of short-lived greenhouse pollutants. The Lancet 374(9707): 1930-1943.
    • Chang J, Delfino RJ, Gillen D, Tjoa T, Nickerson B, Cooper D. 2009. Repeated respiratory hospital encounters among children with asthma and residential proximity to traffic. Occupational & Environmental Medicine 66(2): 90-98.
    • Sahsuvaroglu T, Su J, Brook J, Burnett R, Loeb M, Jerrett M. 2009. Predicting personal nitrogen dioxide exposure in an elderly population: integrating residential indoor and outdoor measurements, fixed-site ambient pollution concentrations, modeled pollutant levels and time-activity patterns. Journal of Toxicology and Environmental Health, Part A 72(23): 1520-1533.