[1
]United States Geological Survey, Columbia, South Carolina 29210, United States
[2
]United States Geological Survey, Iowa City, Iowa 52240, United States
[3
]United States Geological Survey, Lawrenceville, New Jersey 08648, United States
[4
]United States Geological Survey, Reston, Virginia 20192, United States
[5
]Colorado School of Mines, Golden, Colorado 80401, United States
[6
]United States Environmental Protection Agency, Durham, North Carolina 27709, United
States
[7
]United States Geological Survey, Portland, Oregon 97201, United States
[8
]United States Geological Survey, Middleton, Wisconsin 53562, United States
[9
]United States Geological Survey, Lawrence, Kansas 66049, United States
[10
]United States Geological Survey, Lakewood, Colorado 80225, United States
[11
]United States Geological Survey, Lansing, Michigan 48911, United States
[12
]United States Geological Survey, St. Petersburg, Florida 33701, United States
[13
]United States Geological Survey, Sacramento, California 95819, United States
[14
]United States Geological Survey, Kearneysville, West Virginia 25430, United States
[15
]United States Geological Survey, Oklahoma City, Oklahoma 73159, United States
[16
]United States National Institute of Environmental Health Sciences/NIH, Bethesda, Maryland
20892, United States