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.
In contrast, class 2 devices transmit at 2.5 mW with a range of approximately 10 meters or 32 feet. Class 2 devices are the most common Bluetooth transmitters for their fair range with less power requirements than class 1 devices. Most mobile phones and Bluetooth headsets are class 2 devices. Since Bluetooth devices operate in the 2.4 GHz spectrum, they use the same commodity antennas designed for WLAN devices.