{\displaystyle p={\frac {F\cdot {\text{distance}}}{A\cdot {\text{distance}}}}={\frac {\text{Work}}{\text{Volume}}}={\frac {\text{Energy (J)}}{{\text{Volume }}({\text{m}}^{3})}}.} Some meteorologists prefer the hectopascal (hPa) for atmospheric air pressure, which is equivalent to the older unit millibar (mbar). Similar pressures are given in kilopascals (kPa) in most other fields, except aviation where the hecto- prefix is commonly used. The inch of mercury is still used in the United States. Oceanographers usually measure underwater pressure in decibars (dbar) because pressure in the ocean increases by approximately one decibar per metre depth. The standard atmosphere (atm) is an established constant. It is approximately equal to typical air pressure at Earth mean sea level and is defined as 101325 Pa.
Because pressure is commonly measured by its ability to displace a column of liquid in a manometer, pressures are often expressed as a depth of a particular fluid (e.g., centimetres of water, millimetres of mercury or inches of mercury). The most common choices are mercury (Hg) and water; water is nontoxic and readily available, while mercurys high density allows a shorter column (and so a smaller manometer) to be used to measure a given pressure. The pressure exerted by a column of liquid of height h and density ρ is given by the hydrostatic pressure equation p = ρgh, where g is the gravitational acceleration. Fluid density and local gravity can vary from one reading to another depending on local factors, so the height of a fluid column does not define pressure precisely.
Background
Human malaria is native to 97 countries and is the worlds most prevalent vector-borne disease with 212 million new cases in 2015. Any occurrences outside endemic countries are largely imported cases or less commonly malaria with no recent travel history.Airport malaria is defined as malaria acquired at or near an airport through the bite of an infected tropical Anopheles mosquito by a person who has no history of being exposed to the mosquitoes in their natural habitat. Malaria transmission in-flight or on a stop-over is not considered airport malaria. Causes
Although most imported malaria is due to travel by infected humans, airport malaria is specifically caused by the transmission of malaria parasites to a human through the bite of a malaria infected mosquito that has travelled by aircraft on an international flight from a country where malaria is usually found to a country where malaria is usually not found. It occurs at or around the vicinity of the airport. Very few mosquitoes however enter aircraft and of those that do, less than 5% are likely to carry malaria. Of the four different species of the protozoan parasite Plasmodium; Plasmodium falciparum, Plasmodium malariae, Plasmodium vivax and Plasmodium ovale, airport malaria is most commonly the falciparum and less commonly the vivax type. These can only be transmitted by female Anopheles mosquitoes, which bite mainly between dusk and dawn.Five infection pathways have been described: inside the aircraft, inside the airport, around the airport, far from the airport and from luggage.