however, are much more noisy than those for light. The benzene
measurements also reveal a decrease of the benzene levels at
nighttime, as expected due to the lighter night traffic, but quite
surprisingly there is no evident variations in the daytime benzene
levels during the weekend (October 26–27). It is also interesting
to note the peak of benzene measured in the early afternoon of
October 29. Examining the readings of the other sensors in the
same time interval, we can note a sharp decrease of light intensity
and temperature, and an increase in humidity. These readings
suggest that a quick rainstorm has temporarily obscured the
sunlight, while producing congestion in the road traffic and, in
turn, a peak of benzene in the air.