Toxic on EARTH Magazine

A new — and more toxic — normal? Harmful algal blooms find new habitats in changing oceans

Fri, 13 Jan 2017 13:06:09 -0500

An Envisat image of a phytoplankton bloom in the South Atlantic Ocean east of the Falkland Islands on Dec. 2, 2011. Chlorophyll pigment detected by ocean-color sensors on Earth-observing satellites can help identify species in algal blooms and their toxicity. Credit: ESA.

In May 2015, a seizure-wracked sea lion hauled itself ashore on a beach in southern Washington. Testing confirmed it was suffering from domoic acid poisoning, an illness that causes disorientation, seizures and sometimes death that stems from the consumption of fish or shellfish contaminated by a toxic species of algae called Pseudo-nitzschia. To the south, in warm California waters where localized toxic blooms of Pseudo-nitzschia are a near-annual occurrence, sea lion illnesses caused by exposure to domoic acid are common — however, this was a first in Washington. The sick sea lion was euthanized, but its stranding in Washington alerted coastal communities to the massive algae bloom that was engulfing coastal waters from Santa Barbara, Calif., all the way to British Columbia.

Natural arsenic levels in Ohio soils exceed regulatory standards

Tue, 19 Aug 2014 10:44:13 -0400

A new study in which all 842 soil samples taken in Ohio had more arsenic than recommended by the Environmental Protection Agency (EPA) raises the question of what to do when natural background levels in the environment exceed limits set to protect ecosystems and human health.

All that glitters... Acid mine drainage: The toxic legacy of gold mining in South Africa

Thu, 05 Jan 2012 06:41:58 -0500

Mining communities in the Witwatersrand goldfields are often built near, or on top of, tailings piles that contain uranium dust. © Stephan du Toit, 2011

Pumps at the Grootvlei Mine in South Africa's Easter Basin before pumping ceased in early 2011. South African Water Research Commission

In 1947, in a dolomite cave 50 kilometers northwest of Johannesburg, South Africa, anthropologist Robert Broom discovered a 2.05-millionyear- old adult australopithecine skull, one of the oldest and most important hominid fossils ever found. The caves of the Sterkfontein Valley have since produced a treasure trove of australopithecine fossils along with evidence of the early use of stone tools and fire, prompting UNESCO in 1999 to name it the Cradle of Humankind World Heritage Site. For 2 million years, the site has preserved evidence of human origins and evolution — but the activities of modern humans are now threatening its existence.