Related topics: water · pollution

EPA issues violation notice to San Francisco

The Trump administration ratcheted up its feud with California on Wednesday as the Environmental Protection Agency issued a notice accusing San Francisco of violating the federal Clean Water Act.

Lovers of Tuscany's 'paradise' beach have factory to thank

Holidaymakers splash in the turquoise waters of the Rosignano Solvay beach in Tuscany and laze on its pristine white sands—most of them fully aware that the picture-perfect swimming spot owes its allure to a nearby factory.

Choosing trees with a liking for heavy metal

Which species of trees should we be planting in the urban environment to best soak up pollutants containing toxic heavy metals? Stefanos Tsiaras of Aristotle University of Thessaloniki and Theano Samara of the Forest Research ...

Total annihilation for supermassive stars

A renegade star exploding in a distant galaxy has forced astronomers to set aside decades of research and focus on a new breed of supernova that can utterly annihilate its parent star—leaving no remnant behind. The signature ...

Distant 'heavy metal' gas planet is shaped like a football

The scorching hot exoplanet WASP-121b may not be shredding any heavy metal guitar riffs, but it is sending heavy metals such as iron and magnesium into space. The distant planet's atmosphere is so hot that metal is vaporizing ...

page 1 from 23

Heavy metal (chemistry)

A heavy metal is a member of an ill-defined subset of elements that exhibit metallic properties, which would mainly include the transition metals, some metalloids, lanthanides, and actinides. Many different definitions have been proposed—some based on density, some on atomic number or atomic weight, and some on chemical properties or toxicity. The term heavy metal has been called "meaningless and misleading" in an IUPAC technical report due to the contradictory definitions and its lack of a "coherent scientific basis". There is an alternative term toxic metal, for which no consensus of exact definition exists either. As discussed below, depending on context, heavy metal can include elements lighter than carbon and can exclude some of the heaviest metals. Heavy metals occur naturally in the ecosystem with large variations in concentration. Nowadays anthropogenic sources of heavy metals, i.e. pollution, have been introduced to the ecosystem. Waste derived fuels are especially prone to contain heavy metals so they should be a central concern in a consideration of their use.

This text uses material from Wikipedia, licensed under CC BY-SA