ការព្យាករណ៍គុណភាពខ្យល់
ទិន្នន័យគុណភាពខ្យល់ផ្តល់ដោយ៖ UK-AIR, air quality information resource - Defra, UK (uk-air.defra.gov.uk)
Note that the measurement for O3 (ozone) are taken from the station: Glazebury and the measurement for SO2 (sulfur dioxide) are taken from the station: Liverpool Speke