Table 1.

Environmental and demographic characteristics of Tumbes and regions with CKDu

	Tumbes	Andhra Pradesh/Uddanam	El Salvador (coastal region)	Egypt El-Sharkia	Sri Lanka	Nicaragua
Population	240,590	14,807	238,244	8,017,894	21,358,975	206,264
Urbanicity	94.1% (urban)	24% (urban)	67% (urban)	77% (urban)	77% (urban)	81.6% (urban)
Climate	Arid and subtropical	Hot tropical	Tropical	Arid	Tropical	Tropical
Humidity	76%	70–90%	62–100%	Over 90%	70–95%	65–80%
Precipitation	131.4 mm	1067 mm	13 to 155 mm	4 mm (no rain season)	200 mm	181 mm
Temperature	21–40 °C	34.3 °C	23–35 °C	32.6 °C	36 °C	35 °C
Average annual temperature	25.3 °C	31.5 °C	26 °C	26.2 °C	27 °C	32.5 °C
Altitude	Sea level	60–70 m	90 m	4–8 m	81 m	109 m
Agriculture	Rice, lime, banana	Rice coconuts and cashew	Sugarcane	Cotton	Chena, rice cultivations	Banana, sugarcane
Pesticide	Paraquat, methomyl 90SP	Organochlorides	Paraquat	Cadmium, nickel and mercury	Glyphosate	Pyrethroids and chlorpyrifos
Metal contamination	Arsenic	Silica	Arsenic, cadmium	Cadmium	Cadmium	Aluminum, arsenic, lead
Leptospira	0.02–5%	61.8%	–	49.7%	53%	36%
Hypertension rates	26.9%	38.5–615%	30%	–	26%	22%
Type 2 diabetes mellitus	10.3%	7.2–30%	8.8%	–	8.6%	10%
CKDu	< 1%	1.6–4.8%, up to 60%	25%	17.7%	15–21%	19%