Local wind regimes induced by a lake or a shoreline may have a major influence on air pollution dispersion. Pressure differences due to differential heating of the air, e.g., that due to differences in surface characteristics, are the driving forces of lake and land breeze circulations and slope and valley winds. Differences in roughness between land and lake surfaces will cause wind shear and aerodynamic downwash effects at a shoreline. Stability changes in the air result from differences in surface temperature and roughness between land and lake, e.g., when warm unstable air moves out over a cool lake a temperature inversion will develop near the surface giving very poor dispersion conditions in this lower layer. Pollution released in this stable layer may be carried in high concentrations for many miles and cause severe damage as the air moves across a down wind shoreline and advances inland. The information presented is designed to permit an assessment of the probable complexity of the dispersion patterns near a shoreline so that possible requirements for additional meteorological and dispersion information may be determined. Brief descriptions of two actual lakeside sites, one on Lake Erie and the other on Lake Michigan, are given and their relevant characteristics are presented. Natural ventilation was above average at both sites.