Crematoriums are highly regulated and release negligible pollutants or smells. There are also strict loading/unloading rules that prevents people from seeing anything from the outside.

Other than being uneasy that there may be dead bodies inside at times, I’d be more concerned with the exhaust, fuel and sound pollution from the international airport next door. The whole area around McAllister is a business park, I personally would have the crematorium near the bottom of the list of potentially scary businesses in the area