Environment | Higher density, worse air quality and more waste in 2014

The Statistics and Census Service (DSEC) released its 2014 environmental statistics yesterday, revealing higher population density, less rainfall, fewer “good” air quality days, and greater water consumption and waste.
The city’s total land area measured 30.3 square kilometers in 2014, while the population density rose to 20,500 people per square kilometer; compared with 2013, this represents 1,000 more people per square kilometer.
As for the climate, the annual mean air temperature was 22.7 degrees Celsius, up by 0.3°C year-on-year. Total precipitation decreased by 981 millimeters (mm) year-on-year to 1,584 mm, while total duration of sunshine or insolation time increased by 147 hours to 1,871 hours.
The city also recorded fewer days of “poor” air quality last year, but also fewer “good” days than in 2013.
The number of “poor” air quality days recorded at the monitoring stations at Roadside (Rua do Campo) (52 days), the Big Taipa Hill (29 days) and the high density residential area in the Northern District (30 days) decreased by 13 days, 11 days and 10 days respectively.
The monitoring stations at the high-density residential area in the Northern District and the Big Taipa Hill also both recorded a decline in their percentage share of days that boasted “good” air quality, with these shares decreasing by 8.5 and 2.4 percentage points respectively. These two stations recorded an increase in the portion of days where air quality was “moderate.”
Meanwhile, the four monitoring stations that measure fine suspended particulates (PM2.5) recorded the highest PM2.5 index of the year in January, with the monitoring station at Roadside (Rua do Campo) leading at 158.8 micrograms per cubic meter. Acid rain was recorded on 77 days in 2014, down by 7 days year-on-year.
Last year’s total water consumption increased by 6.4 percent year-on-­year to 83,486,000 cubic meters. Water consumption by the business sector (42,697,000 cubic meters) and households (35,266,000 cubic meters) increased by 7.2 percent and 5.2 percent respectively. Meanwhile, the wastewater treatment plants treated an average of 216,917 cubic meters of waste water per day, up by 0.9 percent year-on-year.
In addition, a total of 218,987 tonnes of domestic waste was collected, representing a 5.4-percent increase year-on-year. The volume of waste from the business sector surged by 14.8 percent to 122,906 tonnes, while the volume of solid waste incinerated also increased significantly by 15.3 percent to 457,370 tonnes. The landfill treated 11.5 percent more renovation and construction waste to a total of 4,376,000 cubic meters.