He cited the example of a passenger who inadvertently carried a gun on board a plane in New Orleans, and said such lapses were intolerable.
But the colonists also inadvertently carried pathogens, weeds, and rats.
Ecologists generally define an alien species as one that people inadvertently or deliberately carried to its new location.
It expands its range as boaters inadvertently carry bits of it from lake to lake.
Humans can inadvertently carry the virus from horse to horse by, for instance, petting an infected horse and then touching an uninfected one.
Previous to Stone's paper, most discussion of contamination dealt with the hazards to other planets of satellites and probes inadvertently carrying earth organisms.
The mites are so tiny that they can easily be blown or splashed onto other bushes or carried inadvertently by flying insects.
In the last few weeks, it popped up almost simultaneously in at least 15 more countries, inadvertently carried there by infected passengers on commercial flights.
The reason the introspection was needed, Bonds explained, was that he inadvertently carried a lot of emotional baggage into the season.
Any by inadvertently carrying exotic organisms back to Earth on our spacecraft, we risk the release of biohazardous materials into our own ecosystem.