In fact, the environmental impact of Light-Emitting Diode (LED) is high and, because of their toxicity, should be classified as waste dangerous.
Since last long, they generate little heat and do not contain mercury, the light-emitting diodes (LEDs) appear as the ideal source of light green. But a study by researchers at the University of California, notes that California's standards, the LEDs used for small products such as Christmas lights, traffic signals, and remote controls should be classified as hazardous waste . Julie Schoenung materials engineer and his colleagues have led the subject of nine colors for leaching tests using the Environmental Protection Agency of California determine whether a product is dangerous. The researchers sprayed the LED's and mixed the powder with acid to represent the chemical conditions that meet the LEDs in a landfill. Using mass spectrometry, they measured the amount of metal off of the reaction.
Only one LED, the red one, has failed the Federal test that uses acetic acid resulted in an unacceptable level of lead. Eight out of nine of the diodes have recorded high levels of copper, lead, nickel, silver, using the most stringent standards of California involving nitric acid. Researchers have observed the metal portion of the semiconductor dei LED come gallio e indio, che non hanno stabilito limiti di soglia regolamentare.
Schoenung dice che questi prodotti vanno smaltiti con precauzione per i loro componenti pericolosi. "Le aziende dovrebbero cercare di sostituire questi componenti tossici o predisporre il recupero e la riciclabilità per i loro prodotti."
Megan Schwarzmann , un medico e ricercatore della sanità pubblica presso la University of California, Berkeley , dice che le nuove scoperte non indicano un pericolo per i consumatori durante l'uso del prodotto. Ma dice che lo studio sottolinea la necessità di considerare il ciclo di vita completo del prodotto.
fonte: Chemical & Engineering News
fonte: Chemical & Engineering News
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