1st Generation Pesticides: 1  2500 BC- farmers began using the toxic chemical sulfur to kill off pests from their crops. 2  15th century AD -a variety of chemicals such as, arsenic, hydrogen cyanide, mercury and lead were put to use. 17th century -nicotine sulfate, derived from tobacco leaves was discovered as an effective pesticide and ants were controlled with mixtures of honey and arsenic.
Cell phones communicate with nearby cell towers mainly through radiofrequency (RF) waves, a form of energy in the electromagnetic spectrum between FM radio waves and microwaves. Like FM radio waves, microwaves, visible light, and heat, they are forms of non-ionizing radiation.
Cell towers only transmit around 10 watts usually. Sometimes up to 50 or so in urban areas. Your phone can transmit up to 2 watts. Transmit power does obviously have a big effect on the range of a signal, but it is not nearly as much as you would think due to the 1/r 2 relationship of radio