Black dots are incidences of T-cell lymphoma from the study referenced below Lymphoma appears to be clustered in 3 areas of Houston My research/theory suggests that areas of 1) high commercial aircraft traffic (with additional radars in the aircraft nose) combined with low flight paths over areas of microwave earthstations and pulsed microwave radars will see increased cancer due to electromagnetic induction of microwave radiation reflecting to the Earth/biology below triggering chronic  low-level electrical currents