What can I do if my neighbor's second hand smoke fills my apartment constantly and I keep waking up coughing in the middle of the night? And the Brookside Manor apartment management did not do anything to help the situation ?

Wow that is pretty strange... Are they smoking outside your open window? Are they doing it intentionally? With respect, of course, sometimes we smell things like cigarettes smoke, BBQ smoke, leaves burning, fertilizer, cooking aroma etc but it is not filling our living area. It's bad when we experience stuff like this I don't think Brookside has any legal responsibility to stop a neighbor smoking in his/her area, but they may help you get a air purifier/filter . Ask them directly. If not ask them to help you relocate to another apt but that would probably cost you some of your hard earned cash.

According to CDC (https://www.cdc.gov/tobacco/data_statistics/fact_sheets/secondhand_smoke/health_effects/index.htm) Secondhand smoke is the combination of smoke from the burning end of a cigarette and the smoke breathed out by smokers. Secondhand smoke contains more than 7,000 chemicals. Hundreds are toxic and about 70 can cause cancer. Since the 1964 Surgeon General’s Report, 2.5 million adults who were nonsmokers died because they breathed secondhand smoke. There is no risk-free level of exposure to secondhand smoke. Secondhand smoke causes numerous health problems in infants and children, including more frequent and severe asthma attacks, respiratory infections, ear infections, and sudden infant death syndrome (SIDS). Smoking during pregnancy results in more than 1,000 infant deaths annually. Some of the health conditions caused by secondhand smoke in adults include coronary heart disease, stroke, and lung cancer.