No abstract

These studies show that a relationship exists between traffic volume, proximity t o the highway, engine acceleration us. constant speed, wind direction, and the amount of lead in the air. They also reveal that a marked effect of traffic on the lead content of the air is limited to a rather narrow zone bordering the lee side of the highways. Lead values can be expressed as a quadratic function in time and linear to traffic volume. Particle size studies reveal that 65 of the lead in the air between 30 and 1750 feet from a highway consists of particles under 2 p, and 85 % under 4 p in diameter. ead as a pollutant in the air, on plants, and in soils

The literature was reviewed in order to determine the variables likely to be important in forecasting thunderstorms. A stepwise discriminant analysis was performed on these variables to determine those significantly related to thunderstorm occurrence. Eight variables were selected. These were then used to produce a forecasting equation by means of the linear discriminant analysis technique. This equation was then tested against the Showalter and Total Totals indexes for forecasting skill, and was found to have higher skill.