I’m asthmatic too, it’s so common in Australia. My sister’s childhood friend died from asthma. I don’t know much about salt lamps, but I know how important it is to use a preventer EVERY DAY, even when I’m well. With the appropriate dosage of preventer, I rarely use my Ventolin, yet I keep one in my hand bag & also next to my bed. There are a few HUNDRED people every year who die from asthma in Australia. Use a peak flow meter regularly & get to the doctor if the readings start to decrease. Take asthma seriously!
The plant I believe clearcrystalwater was referring to is called mother-in-law’s tongue. Some other helpful plants are referenced here: http://www.mnn.com/health/healthy-spaces/photos/15-houseplants-for-improving-indoor-air-quality/a-breath-of-fresh-air
Mother-in-law’s Tongue plant (Sansevieria trifasciata)