A traditional fertilizer containing N, P, K would not worry me. Excess nitrogen fertilizer not used by the plants tends to be washed away by rain and irrigation. I am guessing that the landscapers also use pesticides, herbicides, and aquacides. Can you find out the identities of these products that would be of concern? I would think that you would have a right to know this information since this is your living space. You can request the MSDS (Material Safety Data Sheets) information and see the actual chemical components of the products.