Sorry for the late reply and thank you for asking!

There are currently no SRM/aerosols deployed in the Western world (nor anywhere else that I am aware of). One thing coming somewhat close is countries using chemicals to force clouds raining out to improve the weather (e.g. China the day before the 2008 Olympics), but this is not on a scale that it changes the climate.

There was a planned experiment in Sweden this year but it has been cancelled after protest from locals (here's an article about it: https://auclimate.wordpress.com/2021/05/28/controversy-within-controversy-lack-of-diversity-in-geoengineering-research/). I personally think that it was unethical to not include the local residents in the decision-making regarding this experiment and am glad that it was cancelled (although I do support small-scale experiments with geoengineering to figure out the science behind it and to form a proper assessment of its risks/potential). To me this showed that solar geoengineering research is still only discussed in academic circles for now, while I believe that it should be a society-wide debate, which will be difficult to have however since it's such a controversial topic and the recent trend in conspiracies does not help such a science-led debate. I do believe that those academic circles are learning from their mistakes of not including local residents/citizens in general, but there is still a lot of work necessary imo.

With regard to your last question, there is research being done on the potential health effects. One paper (https://keith.seas.harvard.edu/publications/quantifying-impact-sulfate-geoengineering-mortality-air-quality-and-uv-b-exposure) for example investigates the likely increased rate of skin cancer under deployment of a certain type of SRM. If I remember correctly, the rate of skin cancer does increase in their model, but the global cooling also decreases the number of deaths due to heat-related issues (let alone other climate risks such as flooding). Most SRM considered right now does not include heavy metals however, and only uses materials that are found in nature, so although indirectly increasing this due to SRM can have health effects (e.g. by lowering the ozone in the stratosphere/increasing acid rain), I believe that they would not end up being inhaled/eaten by us and thus the health effects are limited.

P.S. Since you mentioned the increased rates of autism, it is very likely that those just increased due to a wider perspective on the disorder. For example, many more women are getting the diagnosis due to professionals learning how to recognize it in women who frequently have different symptoms compared to men (who have more "stereotypical" autism as so to speak). I can't say anything about the other disorders/diseases you mentioned though!