ABSTRACT

ROAD DUST CONTAINS A VARIETY OF HEAVY METALS AND IS A WIDELY USED INDICATOR FOR MONITORING   POLLUTION   AND   ASSESSING    ENVIRONMENTAL   AND   HEALTH   RISKS    IN   URBAN ECOSYSTEMS.  IN THIS  STUDY,  ROAD  DUST  WAS  COLLECTED  FROM  8  REPRESENTATIVE  AREAS  IN MACAO. THE SPATIAL DISTRIBUTION OF HEAVY METAL CONTENT IN ROAD DUST IN MACAO WAS DETERMINED BY EXTRACTING THE HEAVY METAL CONTENT IN EACH SAMPLE. HEAVY METALS IN ROAD DUST ARE MAINLY FOUND ON BUSY ROADS, AND THE PRODUCTION OF THESE HEAVY METALS  MAINLY  COMES  FROM THE  PARTICLES  WORN  OFF  IN  THE  WORK  OF TRANSPORTATION VEHICLES, SUCH AS TIRES, BRAKE PADS, ROAD DUST, AND EMISSIONS FROM EXHAUST PIPES, THESE HEAVY METAL PARTICLES SCATTERED ON THE ROAD WILL REMAIN ON THE ROAD SURFACE FOR A LONG PERIOD AND CAUSE  ENVIRONMENTAL POLLUTION.  THIS  SAMPLING WAS  ALSO  COLLECTED WHEN THERE WAS NO RAINFALL IN MACAO FOR MORE THAN 7 DAYS, WHICH ALSO ENSURED THAT THE HEAVY METAL CONTENT IN ROAD DUST DISTRIBUTED IN TIME AND SPACE WAS AS CLOSE TO ACCURATE DATA AS POSSIBLE. AT THE SAME TIME, IN THIS COLLECTION OF ROAD DUST REGULATIONS, THE SAMPLING IS STRICTLY FOLLOWED BY RECORDING THE AREA, TRAFFIC FLOW, WEATHER, HUMIDITY, AND OTHER FACTORS. THE ADDITION OF A LARGE STATISTICAL ANALYSIS OF VARIABLES HELPED TO CORRELATE  THE  ELEMENTS  STUDIED  WITH  SEVERAL  LOCAL  SOURCES  OF  POLLUTION:  FROM  LOCAL INDUSTRIAL PLANTS  AND RELATED ACTIVITIES, PAVEMENT MODIFICATIONS, POWER PLANTS,  ROAD TRAFFIC, AND THE RESUSPENSION OF PARTICULATE MATTER (RPM). OUR FINDINGS SUGGEST THAT COMBINING CHEMICAL AND ISOTOPIC MONITORING OF ROAD DUST MAY HELP IMPLEMENT MORE EFFECTIVE  ENVIRONMENTAL  MANAGEMENT  MEASURES   TO  REDUCE  ITS  ADVERSE  EFFECTS  ON ECOSYSTEMS AND HUMAN HEALTH. THIS STUDY ANALYZED THE TEMPORAL AND SPATIAL DISTRIBUTION OF HEAVY METALS IN ROAD DUST FROM DIFFERENT LOCATIONS IN MACAO, REVEALING THE CURRENT SITUATION OF HEAVY METAL POLLUTION AND ITS POTENTIAL THREAT TO HUMAN HEALTH. THE RESULTS SHOW THAT HEAVY METALS PRIMARILY ORIGINATED FROM HUMAN ACTIVITIES SUCH AS TRANSPORTATION EMISSIONS, INDUSTRIAL ACTIVITIES, AND ROAD CONSTRUCTION. THROUGH DETAILED ANALYSIS OF THE SAMPLING POINTS  IN  G 1-G8,  IT  WAS  FOUND  THAT  THE  CONCENTRATION  OF  HEAVY  METALS  VARIED SIGNIFICANTLY IN DIFFERENT AREAS, ESPECIALLY IN AREAS WITH HEAVY TRAFFIC FLOW, IN WHICH THE HEAVY METAL CONTENT WAS GENERALLY HIGHER.