Chemical contaminants are chemicals toxic to plants and animals in waterways. The phrase 'chemical contamination' is used to indicate situations where chemicals are either present where they shouldn't be, or are at higher concentrations than they would naturally have occurred.
It would be considered an at bat because the baserunner from second base did not score a run.
The answer is diet, or lifestyle but I recommend diet more
If you go to the Doctor or Tell your parents, that could help!