How are harmful elements and compounds in plants, soils, rocks, and sediments regulated?

Regulatory limits for safe levels of elements in water and foodstuffs are established by the U.S. Environmental Protection Agency (EPA) and the U.S. Food and Drug Administration (FDA). However, there are generally no regulatory limits that scientists can refer to when dealing with plants, soils, rocks, and sediments. Therefore, to determine whether a plant, soil, rock, or sediment contains a 'high or unusual' quantity of a specific element, it is necessary to determine what quantity is 'normal or usual.' These levels are referred to as background or baseline measurements, but they may be somewhat different.

background measurement represents natural concentrations of an element in natural materials that exclude human influence. This measurement represents an idealized situation and is typically more difficult to measure than a baseline.

baseline measurement represents concentrations measured at some point in time and is not generally a true background. Baseline concentrations are typically expressed as a range, not a single value.

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Does the Earth's magnetic field affect human health?

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Does the USGS have reports on the background levels of elements in soils and other surficial materials?

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How frequently are volatile organic compounds (VOCs) detected in groundwater?

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Date published: March 31, 2017

20 Years Researching Harmful Algal Blooms Supports Sustainable Water Supply in Wichita

Two decades of harmful algal bloom, nutrient and sediment research by the U.S. Geological Survey is helping to support Wichita’s long-term vision of a sustainable water supply into the future. Early warning indicators of harmful algal blooms have been developed for Cheney Reservoir, Kansas, according to a new USGS publication done in cooperation with the City of Wichita, Kansas.

Date published: April 13, 2015

Coal-Tar-Sealant Runoff Causes Toxicity and DNA Damage

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Date published: June 16, 2014

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Nearly three-in-ten well-water samples tested from southeast New Hampshire contained metals at concentrations that exceeded U.S. Environmental Protection Agency drinking-water standards and guidelines, according to a recent U.S. Geological Survey study.

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Date published: April 29, 2014

Potentially Harmful Levels of Contaminants Found in Fish in the Columbia River

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Disinfection of Energy Wastewater Can Lead to Toxic Byproducts

Wastewater treatment plants that process waters from oil and gas development were found to discharge elevated levels of toxic chemicals known as brominated disinfection byproducts, according to a new study by the U.S. Geological Survey.

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Many Contaminants Found In Nation’s Streams, But Few Drinking-Water Standards Exceeded, USGS Report Shows

In a look at water-quality conditions of 20 of the country’s largest and most important river basins, the U.S. Geological Survey announced today (June 28, 1999) that streams in areas with significant agricultural or urban development almost always contain complex mixtures of nutrients and pesticides.

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Chesapeake Bay Advisory: Water From Pocomoke River Will Be Tested For Toxics

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Image: Testing Coal-Tar Sealcoats for Toxic PAH Emissions
August 23, 2011

Testing Coal-Tar Sealcoats for Toxic PAH Emissions

A USGS scientist adjusts an air pump used to measure emission of polycyclic aromatic carbons (PAHs) into the air.

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Slimy Summer Swimming: Harmful Algal Blooms in Lakes, Rivers and Streams

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rare earth oxides

These rare-earth oxides are used as tracers to determine which parts of a watershed are eroding. Clockwise from top center: praseodymium, cerium, lanthanum, neodymium, samarium, and gadolinium. Image Number D1115-1. Photo by Peggy Greb, USDA-ARS.

Image: Harmful Algal Blooms

Harmful Algal Blooms

You may notice a green, red or brown film on your favorite boating or swimming area in the summer. This coloring could mean that the water is affected by harmful algal blooms. Harmful algal blooms are an accumulation of tiny organisms known as algae and can release harmful toxins into the environment. Pictured is Gloeotrichia echinulata, showing the entire colony under

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