Dusty Miller leaching into tomatoes?

[Tomatoes]

I learnt today that dusty miller is poisonous - meanwhile it is growing in the same pot as my tomatoes! My tomatoes are just ripening now - do you think poison could have been transferred to them through the soil?

 

[Oliver Buckle]

Can't see it myself; that one plant would 'leech' such stuff into the soil; or another completely different plant would pick it up. It would make a great plot for a murder mystery if it could.

 

[NigelJ]

I learnt today that dusty miller is poisonous

There are at least 5 plants that share this name along with a number of people and pubs. This is the problem with common names.
Ruling out people and pubs; Artemisia stelleriana, found in North America and Asia, is probably the more likely. Some Artemisia are poisonous especially A absinthium (wormwood) used to make absinthe. A stelleriana has been used as a flea and midge repellent, also in brewing. I wouldn't worry about anything moving through the soil to your tomato plants.
Curiously tomatoes were originally not eaten in the UK as they were considered poisonous and the leaves are.