Mueang Samut Sakhon District

Mueang Samut Sakhon (, ) is the capital district ("amphoe mueang") of Samut Sakhon Province, central Thailand.
History.
"Mueang" Tha Chin dates back to the Ayutthaya Kingdom. The city was managed by the Defence ministry. King Maha Chakkraphat ordered "Mueang" Sakhon Buri to be established. King Mongkut (Rama IV) changed the city name to Samut Sakhon. In 1897 Mueang Samut Sakhon a district.
Locals still refer to Mueang Samut Sakhon District by its old name, "Mahachai".
Geography.
Neighboring districts are (from the west clockwise): Mueang Samut Songkhram of Samut Songkhram Province; Ban Phaeo and Krathum Baen of Samut Sakhon Province; and Bang Bon and Bang Khun Thian of Bangkok. To the south is the Bay of Bangkok.
Environment.
Samut Sakhon Province has more than 6,000 small- and medium-sized factories, many of them in this district. Soil and water samples from the industrial area of Mueang District were found to be contaminated with high levels of arsenic, lead, cadmium, chromium, zinc, copper, and nickel. High levels of persistent organic pollutants (POPS), byproducts of industrial processes, were present in eggs from free-range chickens. An egg tested by researchers was found to have 84 nanograms per kilogram of dioxins and furans, a level 33 times higher than the safety limit observed by the European Union.
Administration.
The district is divided into 18 subdistricts ("tambons"), which are further subdivided into 116 villages ("mubans"). Samut Sakhon itself has city status ("thesaban nakhon") and covers the three subdistricts Maha Chai, Tha Chalom, and Krokkrak. Bang Pla is a subdistrict municipality ("thesaban tambon") which covers parts of the same-named subdistrict. Three other subdistricts completely form a subdistrict municipality: Na Di, Bang Ya Phraek and Tha Chin. The non-municipal area is administered by 12 tambon administrative organizations (TAO).