Vox - Attempts to stop the leak have been unsuccessful... Two substances are coming out of the well, creating a long-term and a short-term problem.
First, the leaking gas contains enormous amounts of methane, which is a highly potent greenhouse gas. It doesn't last as long in the atmosphere as carbon dioxide, but it is much more effective at trapping heat while it's there — 25 times as potent as CO2 over a 100-year time period, and some 84 times as potent over a 20-year period.
And while methane is nontoxic — as far as scientists know, breathing it, except at very high doses, has no long-term ill effect — it does contribute to smog, a perennial problem in LA.
As of late last month, the California Air Resources Board estimated that the well had spewed up to 1.9 billion standard cubic feet of natural gas, the greenhouse gas equivalent of 1.6 million metric tons of carbon dioxide, as much as 330,000 cars pollute in a year. Yet only 2 percent of what's stored in the facility has been lost, and there are months to go before the leak is stopped.
The second product of the well is mercaptan, a stinky chemical added to (odorless) natural gas so that people can detect a leak. Though mercaptan is also reported to have no long-term ill effects, the giant stink cloud covering Porter Ranch has led to reports of dizziness, nausea, nosebleeds, and vomiting among both people and pets. (Here's a Health Department assessment.) What's happening to nearby residents?
Robert F. Kennedy Jr., - Their animals are dying… their fish are dying in their
fish bowls, their dogs are dying, their cats are getting sick. And their
children are getting sick — they’re suffering nose bleeds, they’re
suffering terrible debilitating migraine headaches, asthma attacks,
respiratory infections, eye infections, ear infections, stomach
ailments… The health impact — it’s not just methane coming out of that hole…
This is global crisis, more importantly this is a local crisis. Because
not only do you have methane — you have benzene, toluene, xylene, which
are carcinogenic. You have hydrogen sulfide, sulfur dioxide — which are
neurotoxic, which can injure your brain, affect memory, injure your
kidneys, your liver, your other bodily organs. There’s also a lot of radon gas being measured in the area.