What environmental conditions may adversely affect Nutriway Zinc + selenium?

Yes, it can be taken with other food supplements. However, it is important to read the label (nutrient levels and daily dosage) of all the products to determine if you are staying within the safety limits. Consuming excessive amounts of nutrients may cause one to exceed the established levels of safety.
The National Health & Medical Research Council in Australia has established an Upper Intake Level of 400 µg selenium and 40 mg zinc/day for adults, meaning: A long-term maximum intake of these amounts from all sources (food, fortified food, food supplements) is unlikely to pose a risk of adverse health effects.