I hadn't heard anything about this until a friend of mine pointed out an article to me.

Apparently there are some major health concerns for people that use 3D Printers.

UFPs are particularly relevant from a health perspective because they deposit efficiently in both the pulmonary and alveolar regions of the lung, as well as in head airways. Deposition in head airways can also lead to translocation to the brain via the olfactory nerve. The high surface areas associated with UFPs also lead to high concentrations of other adsorbed or condensed compounds. Several recent epidemiological studies have shown that elevated UFP number concentrations are associated with adverse health effects, including total and cardio-respiratory mortality, hospital admissions for stroke, and asthma symptoms.
Also ABS printers are a lot worse than PLA printers.

Do you guys think there is really a big concern, or is it just people that are trying to find the negatives of 3D Printing?

The article also mentions that cooking, and burning candles create some of these same toxins.