These gases are accumulating in the atmosphere, thanks to our pollution.

Rinks don't usually recirculate their air, so the gases accumulate.

The gas seeps into basements and can accumulate in high concentrations in unventilated areas.

If not properly vented, that gas could have accumulated into an explosive concentration.

Global warming occurs when such gases, chiefly carbon dioxide, accumulate in the atmosphere.

But it was enough to confirm that the gas really is accumulating.

The gas did accumulate more slowly than usual last year; but now the rate seems to be picking up again.

Global warming occurs when such gases accumulate in the atmosphere, trapping heat.

When wrapped in a sack, its gas accumulates for 1 day and you can use it as a love potion.

The gases vesiculate and accumulate as they rise through the magma conduit.