I am small, but when I gather with all my relatives I become big.
I can come from soil, road, humans, animals, insects, volcanic eruptions, and pollution.
I am found in cars, homes, offices, stores, and storage places.
I gather with my relatives to collect on beds, televisions, computers, carpets, furniture, plants, curtains, and hidden places.
Sad to say so far my relatives and I are of no worth.
We are also seldom wanted.
What am i?