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Using GIS to link SEER-Medicare and California pesticide data: a population-based case-control study of pesticide exposure and hepatocellular carcinoma risk

VoPham, Trang (2015) Using GIS to link SEER-Medicare and California pesticide data: a population-based case-control study of pesticide exposure and hepatocellular carcinoma risk. Doctoral Dissertation, University of Pittsburgh. (Unpublished)

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Geographic information systems (GIS), used to analyze spatial data, represent a powerful method to study human health. This research demonstrates the usage of GIS in (1) designing a pesticide exposure metric and (2) linking population-based data sources to conduct an epidemiologic study examining the association between pesticide exposure and hepatocellular carcinoma (HCC).
The first study presents a new GIS method to estimate individual-level agricultural pesticide exposure in California. Landsat remotely sensed satellite images were classified into crop fields and matched to California Pesticide Use Report (PUR) agricultural pesticide application data. Pesticide exposure was calculated using pesticide-treated crop fields intersecting a 500-meter buffer around geocoded locations. Compared to the standard GIS method of matching PUR data to infrequently updated crop land use surveys (LUS’s), our method was able to match significantly more PUR temporary crop pesticide applications to Landsat vs. LUS crops (65.4% vs. 52.4%; n=2,466; McNemar’s p<0.0001).
The second study explored different ways of scaling up Public Land Survey System (PLSS) section pesticide data, the geographic level of reporting for PURs, to the ZIP Code level. We observed substantial agreement between area-weighted ZIP Code pesticide application rates and gold standard census block rates in rural areas (weighted kappa 0.63; 95% confidence interval [CI] 0.57, 0.69). Area weighting was used to estimate pesticide exposure in the third study.
The third (and primary) study was a population-based case-control study examining the association between agricultural pesticide exposure and hepatocellular carcinoma in California via implementing a novel data linkage between Surveillance, Epidemiology, and End Results (SEER)-Medicare and PURs using Medicare ZIP Codes in a GIS. Among rural California residents, previous annual ZIP Code exposure to over 0.06 applied organochlorine pounds per acre significantly increased the risk of developing HCC after adjusting for liver disease and diabetes (odds ratio 1.52; 95% CI 1.02, 2.28; p=0.0415). This is the first epidemiologic study using GIS to examine pesticide exposure and HCC.
The public health significance of this research is related to using epidemiologic, GIS, and biostatistical methods to form a better understanding of pesticides as a potential risk factor for HCC, which is increasing in incidence.


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Item Type: University of Pittsburgh ETD
Status: Unpublished
CreatorsEmailPitt UsernameORCID
VoPham, Trangtmv7@pitt.eduTMV70000-0003-4787-1201
ETD Committee:
TitleMemberEmail AddressPitt UsernameORCID
Committee ChairWeissfeld, Joel Ljwepid@pitt.eduJWEPID
Committee MemberBrooks, Maria Mbrooks@edc.pitt.eduMBROOKS
Committee MemberYuan, Jian-Minyuanj@upmc.eduYUANJ
Committee MemberTalbott, Evelyn O.eot1@pitt.eduEOT1
Committee MemberChang, Chung Chouchangj@pitt.eduCHANGJ
Committee MemberRuddell,
Date: 28 January 2015
Date Type: Publication
Defense Date: 4 December 2014
Approval Date: 28 January 2015
Submission Date: 20 November 2014
Access Restriction: 1 year -- Restrict access to University of Pittsburgh for a period of 1 year.
Number of Pages: 219
Institution: University of Pittsburgh
Schools and Programs: School of Public Health > Epidemiology
Degree: PhD - Doctor of Philosophy
Thesis Type: Doctoral Dissertation
Refereed: Yes
Uncontrolled Keywords: hepatocellular carcinoma; pesticides; GIS; data linkage; cancer epidemiology
Date Deposited: 28 Jan 2015 17:03
Last Modified: 19 Dec 2016 14:42


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