Amongst the agro-based industries, pollution from palm oil and rubber processing mills is the most severe. Wastes from these industries contain very high concentrations of organic material, suspended solids, nitrogen and phosphorus, while rejected agricultural materials such as straw, leaves and other by-products, which are burned, dumped and disposed of, account for nearly half of all agricultural production. In Peninsular Malaysia, a total of 4.2 million tons of crop residue and 2.3 million tons of livestock waste were produced. Agricultural waste from livestock farms and pesticides and fertilizers constitute the second highest source of organic pollutants polluting our rivers and coastal waters, second only to sewage. From 1986 to 1990, agricultural waste contributed 13 percent of the total BOD pollution load.
It has been estimated that 10 to 25 percent of the agricultural organic waste from animal effluents, mostly from pig farms adjacent to rivers, are dumped into our coastal waters. Environmental quality regulations have somewhat contro y is the most polluting industry. The worst polluters are wood-based, palm oil, food processing non-metals, textiles, rubber products, iron and steel industries. The main sources of air pollution in Malaysia are motor vehicles, power stations, industrial fuel burning and processes, domestic fuel burning, burning of municipal and industrial waste. Power stations and industrial boilers use high sulphur fuel oil producing large quantities of sulphur dioxide. Sulphur dioxide emissions from vehicles are on the rise. Lead pollution, one of the principal forms of air pollutants in Malaysia, is entirely due to vehicle emissions. Suspended particulate matter is the other principal pollutant. Lead emission declined for a while after the introduction of unleaded petrol, but levels are still quite high in certain localities and continue to pose a serious health hazard to children.
In 1991, vehicle emissions contributed 75 percent of the total emissions into the air, an increase of 12 percent over 1987. Kuala Lumpur is now one of 15 Asian cities that have the greatest levels of pollution from TSP: the average reported suspended levels at 53 percent of monitoring stations far exceed WHO standards. The five states with the largest number of air polluters are Selangor, Perak, Federal Territory Kuala Lumpur, Penang and Johor. As urbanization and industrialization become more intensified, the situation will worsen unless due consideration is given to the incorporation of air pollution control measures in development planning.