There are many filters that can filter out things like lead and arsenic as well as things like Giardia. You can research which filters do what on websites I will post below. We use several filters and a UV system just for drinking water. RO systems get rid of turbidity and only RO systems do this. We have not felt a need for RO but we do have an inexpensive UV system which runs under $150US. I have a 10 micron filter canister where I connect to the pedestal tap in any RV park to filter all water coming into the RV and into the fresh tank. I then have a 5 micron which filters all water coming into the RV whether it be from the fresh water tank or the tap. Under the sink we have the UV system and a 0.5 micron coconut shell charcoal filter for drinking water only. In my opinion this provides us with safe water wherever we go. We use it in the US as well. I have read reviews of bottled water and there have been some well known so called pure water sold in the US that do not meet standards. I have seen the large garafons in Mexico being filled from trucks with the garafons sitting on the sidewalk. I have no idea where the water comes from or if it is actually purified. So we have our own system. This is the only guaranty that you are truly getting purified water. We have been using this system for years and have friends with similar systems. We have never gotten sick from drinking water from this system. Total investment is under $200. Be safe and sure by purifying your own water.
http://www.h2osplashwaterfilters.com/ulvistun.html
https://www.filtersfast.com/P-Hydronix-SMCB-2510-Water-Filter.asp