advantages and disadvantages

利点と欠点　メリットとデメリット　長所と短所

The only/one good thing about COVID-19 is that air contamination has gone down worldwide.

Air pollution has gone down worldwide because of COVID-19 lockdowns.

A good thing about,,,

What's good/not good about...

pollution 汚染・公害　contamination 汚染・異物混入

air pollution/marine pollution/environmental pollution

radioactive contamination/contaminated water/be contaminated with...

Working from home has both advantages and disadvantages.