Cold fronts bring cooler, cleaner air from Canada and therefore alleviate air pollution. On the other hand, terrain can cause inversion layers which exacerbate the problem. The warm air layer acts like a blanket on the smog layer, preventing it from dissipating higher in the atmosphere. This EPA web site discusses air quality in New England and inversion layers
http://www.epa.gov/region1/airquality/partic.html

Here is a link to air quality reports for Rhode Island.
http://www.airnow.gov/index.cfm?action=airnow.displaymaps&StateID=47&Pollutant=PM2.5
I notice now that air quality is good, but by changing the date with the scroll down menu to a summer month, it is clear that air quality is a major issue then. This is consistent with inversion layers being a pivotal factor.

A significant water pollution problem in most states is non-point source pollution. Traditional regulatory controls have excelled at addressing end-of-the-pipe pollution sources, such as industrial and wastewater treatment plant discharges. However road runoff, septic system pollution, lawn fertilizer, and animal waste are more difficult to manage. Here is a link to Rhode Island's nonpoint source pollution management plan: http://www.planning.state.ri.us/sgp/pdf/731.pdf.

Another pollution problem that is exacerbated by climatic conditions is red tide, an algal bloom caused by Alexandrium. This microorganism's growth is encouraged by agricultural run-off. Eutrophication results, in which the algae consume all the oxygen in the water killing other marine organisms. Dry sunny periods followed by a sudden storm can encourage Alexandrium to multiply, and winds, tides, and currents can act to contain and concentrate the organisms in one place. Some have suggested that hurricanes play a role in this phenomenon as well (Source: Hu, C., et al. 2006. Hurricanes, submarine groundwater discharge, and Florida's red tides. Geophysical Research Letters 33: L11601, doi:10.1029/2005GL025449.) You can also explore this EPA web site for more information on New England red tides:
http://epa.gov/boston/topics/water/redtide.html

People are affected by red tide primarily because of shellfish poisoning that can occur if contaminated shellfish are eaten. Of course the dying of marine life has a negative effect on the local fishing industry. Air pollution has many harmful health effects, including acute onset or exacerbation of asthma and cardiovascular disease, and premature death (see Dockery, D.W., and C.A. Pope. "Outdoor Air I: Particulates." In K. Steenland and D.A. Savitz (eds.), Topics in Environmental Epidemiology. New York, NY: Oxford University Press, 1997).