how could they be?

My take is this:

Use battery power only if you need the benefit of a not-hot light source (need it to be windproof, childproof, petproof, shake-proof; or if using combustible material as lantern; or if other thermal concerns are at stake.)

Tiny batteries, even if recycled, require a lot of energy to produce, ship, dispose/recycle. If the candle-thing breaks, it's trash, too.

Sorry, but I don't see how tea lights produce a quite a lot of pollution.

From the burning? Negligible pollution.

From the throwing away of the leftover plastic cuppy? If you feel concerned about trashing of the plastic/metal holder, you could buy a block of parafin, make a cotton string wick, melt the wax and reuse the empty tea light cup again and again.

I must be missing something.

Don't fee badly since you've already bought them, Shannon. Try to find the positives.

As far as a direct comparison, I think it depends on how often you use them, honestly. A lot of wax tea lights are only good for a couple of hours at best. I think we all agree soy is far better than parafin, but regardless, yes, there will be a lot of direct "pollution." You can see it in the soot that they leave on walls, ceilings, even table tops around them.
(Unless they're recycled plastic, etc., it may be far less pollution in the long run, though, to go with a wicked candle.)
However the battery operated ones will give you thousands of hours. They do make some that are LED as well, so there's another plus.

I went back and forth with candles or no candles for our wedding and essentially decided that since we were doing a tent wedding we'd like the added ambience. It was in an Arboretum, so I was wary of the open flame. I bought LED battery operated lights and still feel somewhat comfortable with the decision. (We had an near worst-case scenario and had a storm and the power actually went out in the tent--band, lights, everything. I felt pretty smart with the candles and other lights then.) I've also been able to give them out to my family to use for their pumkins this year--and probably years to follow. Far less hazard there, too.

So don't beat yourself up too badly. I'm sure I just opened myself up to some of the abuse too, but I think there are positives and negatives on both sides. Probably one clear winner, but I'm just trying to make you feel a bit better about the choice.

For a special event, a crowded gathering, or frequent use in your own home, I am beginning to think the battery candles might be the wiser move.

Although I have not experienced the thousands of hours of light from the battery lights, I can see where it could really be nice for a season or two of frequent use, or something like that. My kids use them with their pretend firefighter toys, and love to turn them on and off, over and over. Maybe that shortens the life.

Also? I just read about how paraffin is unhealthier than I realized, albeit on a site that sells bees wax candles (honeyflowfarms dot com.)

They say:
Fragrant beeswax candles burn longer and cleaner than ordinary wax candles, and give off more light and heat than other waxes and there's no dripping.

Paraffin is basically the grayish left over sludge produced by petroleum refineries. This paraffin residue is bleached with toxic chemicals and then used to mass produce your average candle. Paraffin waxes contain aromatic compounds which are released when a candle is burned. These compounds have been proven to be carcinogenic.

As paraffin wax burns it creates a black soot that coats your walls ceilings and lungs. This petro-soot is as harmful as second-hand tobacco smoke.

Some paraffin candles emit such hazardous pollutants as acetone, benzene and lead. These harmful substances impair the quality of indoor air.

Candles made with paraffin wax (the fumes of which have also caused kidney and bladder tumors in laboratory animals) may cause sooty deposits in your house.

Initially, beeswax candles may seem to be more expensive than paraffin candles, yet paraffin wax burns away much quicker than beeswax nullifying any price disparity.

PS--Greenjilly, I like your comment. Thanks for pointing out the other side so kindly.

Splomo, do you light entirely through candles and oil lamps? otherwise take the info on black soot with a pinch of salt.

A blow down on a very green wood fire will cause sooty deposits in your house. Be wary of words like "may" and "some" in *any* piece of informative writing, especially if its on a commercial site.