Air Pollutions- room for improvement

VEHICLES and power plants that generate the electricity that we use, were the main air polluters last year. Power stations emitted half of all the soot that clouded our sky, and also half of the total sulphur dioxide (a pungent gas which irritates the respiratory system and forms acid rain).

Motor vehicles, vans and lorries in particular, spewed the most oxides of nitrogen and carbon monoxide, gases which lead to respiratory ailments.

Foul air: Nationwide, the annual averages of sulphur dioxide, oxides of nitrogen, carbon monoxide and ozone were below guidelines, but there is concern over the effects of chronic, long-term exposure.

Klang Valley folks breathed in unhealthy air quality 7% of the time last year, and moderate air quality 70% of the time. The air was good only 23% of the time. The valley is prone to air pollution due to its geographical position, industrial and commercial activities, dense population and traffic.

Nationwide, the annual averages of sulphur dioxide, oxides of nitrogen, carbon monoxide and ozone were below guidelines, but there is concern over the effects of chronic, long-term exposure. Ground level ozone is of concern as continuous exposure aggravates respiratory ailments, harms vegetation, and leads to smog. Ozone forms when oxides of nitrogen react with hydrocarbons and volatile organic compounds in the presence of heat and sunlight.

Murky flows

The main river pollutants are domestic sewage, waste from livestock farms, runoffs from towns, silt from earthworks, leachate from rubbish dumps, runoffs from farms, litter from riverside squatters and mining waste

Last year, 80 river basins were deemed clean, 59 slightly polluted and seven, polluted. This is a marked improvement from 2005, when 80 river basins were clean, 51 slightly polluted and 15 polluted. The seven polluted rivers were Pinang, Juru, Buloh, Danga, Tebrau, Segget and Pasir Gudang.

Last year, domestic sewage and discharges from latex-based factories, agro-based industries and manufacturing industries, fouled 22 river basins.

Domestic sewage and livestock farming waste soiled 41 river basins while earthworks and land clearing turned 42 river basins murky.

Tainted groundwater

Arsenic levels were high in groundwater near a radioactive waste landfill, solid waste landfills, municipal water supply sources and agricultural areas. Groundwater near waste dumps was also contaminated with iron, lead, manganese, phenol and faecal bacteria.

Contaminated seas

Our marine waters showed a higher of Escherichia coli, mercury and arsenic levels last year than the year before. However, levels of suspended solids, oil and grease, copper, lead, cadmium and chromium dropped.

The faecal bacteria E. coli was the dominant pollutant in waters off 71 islands, which included resort islands, marine parks and protected islands. This is because of the discharge of raw or poorly treated domestic sewage.

Pollution by silt was the worst the coasts of Kedah, Perak and Negri Sembilan. Oil and grease pollution were mostly seen in Terengganu, Pahang and Negri Sembilan. E. coli levels were highest off the coasts of Perlis, Kedah, Negri Sembilan and Penang island.

Lead contamination was evident in Terengganu, Kelantan and Perak waters.

Our seas are polluted by rubbish, silt, heavy metals and sewage.

Toxic discards

Hazardous waste thrown out by industries more than doubled in the past two years, from 548,916 tonnes to 1,103,457 tonnes. The hike was due to the addition of electronic waste and gypsum waste (511,929 tonnes) from two generators which were previously not reported.

Gypsum, oil and hydrocarbon, dross, heavy metal sludge, mineral sludge and e-waste form the bulk of the waste. The waste had mostly come from industries dealing with chemicals, electronics, metals, pharmaceuticals, industrial gas, rubber and plastic, petroleum/oleo chemicals and batteries, as well as from automotive workshops.

By TAN CHENG LI