Dryer Sheets typically have a plethora of chemicals that are considered carcinogens: benzyl acetate, linked to pancreatic cancer; benzyl alcohol, which can cause upper respitory tract irritation; and ethonal, which is on the EPA's list of hazardous waste, and can cause central nervous system disorders; alpha-terpineol, a little respiratory problem causing chem that can lead to fatal edema and more central nervous system damage. There's more. I could go on. But I won't. Too much information could potentially cause more central nervous system damage and I'm hoping that you get the point. Get some blue balls and save your life! Now that's a tag line you don't see everyday.
Of course, there are additional options besides the dryer balls. Hang drying being the most safe and economical, but of course not all of us have Julie Andrew-like fields of green. I came up with the idea of just putting up a tension shower rod across my laundry room for hang drying. 'Tis not too bad, but if you have the space, you could instead choose a folding dryer rack.
Whatever your choice, make it a good one, and if you absolutely cannot part with your beloved dryer sheets, and have no interest in dryer balls bouncing around your dryer, than at least choose an environmentally sound brand, such as Seventh Generation.
"After enlightenment, the laundry." - Zen proverb