If the seals were going on the turbo, the give-away would be oily smoke on pullaway starts (stop signs, redlights, stop-and-go traffic, etc.). It probably wouldn't be burning very much oil, however, as the leak would be tiny - but it gets smoky because it's under pressure and the atomized oil burns nicely in the exhaust pipe.

The turbo has two external oil connections. One is the oil supply at the top, with a crushed metal gasket. The other is the oil return line which has a synthetic composite seal. This latter seal has been reported as susceptible to leaking. If you're worried, have this connection inspected for signs of coking (baked oil around the lip of the seal). Serious coking can choke off the return line, thus impeding the flow of oil. The result is the oil supply looking for another means of exit - the oil seals! If you have this line checked, make sure to have a new seal installed - NEVER reinstall the old one.

But sleep well: this scenario is unlikely as the Volvo turbo is durable, your car is young, and you're taking good care of it. Most likey the leak is elsewhere, and there are known trouble spots (easily fixed) in this regard.

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(98 S70 T5SE misc mods, mostly lighting) (92 940GLE)