Inside rural homes, the source/sources of Nitrogen Oxide Pollution may be :…

Concept

Fuel-burning household appliances can generate nitrogen oxides because high-temperature combustion oxidizes nitrogen in the air. Indoor exposure increases when combustion products enter living spaces or ventilation is inadequate.

The source test is therefore whether each listed device burns a fuel and can release combustion gases indoors; it is not limited to one particular fuel.

Application

• An unvented gas stove releases its combustion products directly into the room, and nitrogen dioxide can be among them.

• A wood stove burns solid fuel; leakage, back-drafting, or inadequate venting can introduce nitrogen oxides and other combustion products indoors.

• A kerosene heater burns liquid fuel and is a recognized indoor source of nitrogen dioxide, especially when unvented.

Contrast

• The code “(a) and (b) only” omits the kerosene-heater source.

• The code “(b) and (c) only” omits the unvented-gas-stove source.

• The code “(b) only” omits both the unvented gas stove and the kerosene heater.

Cross-check

The U.S. Environmental Protection Agency lists gas stoves, woodstoves, and kerosene heaters among indoor combustion-product sources and identifies nitrogen dioxide as a major pollutant from such combustion. Thus all three statements, (a), (b), and (c), are included.