QUINCY, Mass. — Residents of a Quincy senior apartment complex near the ocean are used to the full spectrum of sea scents wafting over their building.

But the persistent rotten egg smell that has lingered over The Moorings at Squantum Gardens for about six week is becoming unbearable, and so far, remains unexplained.

The city hired chemists to test water samples for the presence of bacteria that could explain the smell. They came back negative.

A city councilor suggested it was red tide. The state Division of Marine Fisheries says that may not be the cause, although another type of algae may be responsible.

A local clammer thinks it may be rotting shellfish killed by a virus.

City spokesman Christopher Walker tells The Patriot Ledger (http://bit.ly/12gulet) residents just have to let nature run its course.