Polycyclic aromatic hydrocarbons (PAHs) cycling and fates in Galveston Bay, Texas, USA.

Gilbert T Rowe,Terry L Wade,Thomas Heathman,Peter H Santschi,John Sullivan,Harshica Fernando,Cornelis Elferink,G A Shakeel Ansari,Antonietta Quigg,Sharon Petronella Croisant

doi:10.1371/journal.pone.0243734

Abstract

The cycling and fate of polycyclic aromatic hydrocarbons (PAHs) is not well understood in estuarine systems. It is critical now more than ever given the increased ecosystem pressures on these critical coastal habitats. A budget of PAHs and cycling has been created for Galveston Bay (Texas) in the northwestern Gulf of Mexico, an estuary surrounded by 30–50% of the US capacity of oil refineries and chemical industry. We estimate that approximately 3 to 4 mt per year of pyrogenic PAHs are introduced to Galveston Bay via gaseous exchange from the atmosphere (ca. 2 mt/year) in addition to numerous spills of petrogenic PAHs from oil and gas operations (ca. 1.0 to 1.9 mt/year). PAHs are cycled through and stored in the biota, and ca. 20 to 30% of the total (0.8 to 1.5 mt per year) are estimated to be buried in the sediments. Oysters concentrate PAHs to levels above their surroundings (water and sediments) and contain substantially greater concentrations than other fish catch (shrimp, blue crabs and fin fish). Smaller organisms (infaunal invertebrates, phytoplankton and zooplankton) might also retain a significant fraction of the total, but direct evidence for this is lacking. The amount of PAHs delivered to humans in seafood, based on reported landings, is trivially small compared to the total inputs, sediment accumulation and other possible fates (metabolic remineralization, export in tides, etc.), which remain poorly known. The generally higher concentrations in biota from Galveston Bay compared to other coastal habitats can be attributed to both intermittent spills of gas and oil and the bay's close proximity to high production of pyrogenic PAHs within the urban industrial complex of the city of Houston as well as periodic flood events that transport PAHs from land surfaces to the Bay.

Highlights

The environmental, human health and economic consequences of oil spills have been recently reviewed [1,2,3,4]
Data from ADDOMEx/ADDOMEx-2 is publicly available through the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC; https:// gulfresearchinitiative.org/); no new data was deposited in relation to the current study
We calculate that about 80% of the polycyclic aromatic hydrocarbons (PAHs) loading still resides in Galveston Bay sediments, but due to their large areal extent, concentrations are moderate

Summary

Introduction

The environmental, human health and economic consequences of oil spills have been recently reviewed [1,2,3,4]. Data from ADDOMEx/ADDOMEx-2 is publicly available through the Gulf of Mexico Research Initiative Information and Data Cooperative (GRIIDC; https:// gulfresearchinitiative.org/); no new data was deposited in relation to the current study. TW’s participation on this publication was made possible, in part, by NIH grant P42 ES027704. None of the authors have received salary for preparing this manuscript from the above sources. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section

Methods

Results

Conclusion