Prevalence of PBC near superfund toxic waste sites

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Hepatology 43: 525-531 (2006)

Increased prevalence of primary biliary cirrhosis near superfund

toxic waste sites.

Aftab Ala 1 2, Carmen M. Stanca 1, Moueen Bu-Ghanim 1, Imad Ahmado

3, D. Branch 1, D. Schiano 1, ph A. Odin 1,

Bach 1

1Mount Sinai School of Medicine, New York, NY

2Royal Free and University College Medical School, London, UK

3University of Chicago School of Medicine, Chicago, IL

Funded by:

Artzt Family PBC Foundation

NIDDK

British Transplant Society St 's Fellowship

Health Resources and Services Administration; Grant Number: 231-00-

0115

Abstract

Primary biliary cirrhosis (PBC) and primary sclerosing cholangitis

(PSC) are uncommon liver diseases of unknown etiology. Reported

clustering of PBC cases may be due to environmental factors.

Individuals with PBC have a high prevalence of thyroid disease and

thyroid disease is reportedly more prevalent near Superfund toxic

waste sites (SFS). The objective of this study was to examine the

prevalence and potential clustering of individuals with PBC and PSC

near SFS. De-identified clinical and demographic data were used to

determine the observed prevalence for each New York City zip code (n

= 174) and borough (n = 5) of patients with PBC (PBC-OLT) or PSC

(PSC-OLT) who were listed for liver transplantation. The expected

prevalence was calculated using Organ Procurement and Transfer

Network (OPTN) and U.S. Census data. Both PBC-OLT patients and

patients not listed for liver transplantation (PBC-MSSM) were

included in the cluster analysis. Prevalence ratios of PBC-OLT and

PSC-OLT cases were compared for each zip code and for each borough

with regard to the proximity or density of SFS, respectively.

SaTScan software was used to identify clusters of PBC-OLT cases and

PBC-MSSM cases. Prevalence ratio of PBC-OLT, not PSC-OLT, was

significantly higher in zip codes containing or adjacent to SFS

(1.225 vs. 0.670, respectively, P = .025). The borough of Staten

Island had the highest prevalence ratio of PBC-OLT cases and density

of SFS. Significant clusters of both PBC-OLT and PBC-MSSM were

identified surrounding SFS. In conclusion, toxin exposure may be a

risk factor influencing the clustering of PBC cases.