Polluting two-stroke engines under fire

Engines are bad for the environment and for one's health, experts warn in an effort to get them better regulated.

ABU DHABI // Small motorcycles, karting buggies and small watercraft should be better regulated because their engines can have a significant negative impact on the environment, says a local racing enthusiast.

Virtually all cars and large boats use lower-emission four-stroke engines, while smaller boats, scooters and motorcycles rely on older-style two-stroke engines.

The Dubai-based architect Graham Henderson, who runs a drag race team called Herbie Henderson Racing, wants to see a change in the regulations at motor sports events where only two-stroke engines are used.

"Twenty-five per cent of fuel and required oil that conventional two-strokes use is unburned and emitted directly into the air, and young karters breathe this into their lungs at an alarming rate," said the father of three. "I don't want my kids inhaling these fumes, which are carcinogenic."

The impact of these engines on the environment is an emerging area of study, and there has been no local research published on the topic. Scientists in the West, however, have been exploring the issue for a decade. Bryan Willson, a professor of mechanical engineering and the director of the engines and energy conversion laboratory at Colorado State University, said that with a traditional two-stroke engine "you end up losing a very significant amount of fuel … In rough terms, each of these is as polluting as 50 modern vehicles".

The issue is significant in India, the Philippines and Thailand, where there are roughly 50 million two-stroke vehicles - the equivalent of around 2.5 billion modern cars in terms of pollution impact, Prof Willson said.

The use of motorcycles and scooters in the UAE is more limited. No statistics are available on the number and types of other watercraft here, but the Ministry of Environment and Water has capped the number of fishing boats at 5,500.

Besides air pollution, two-stroke engines can cause significant damage to bodies of water, too. They leak persistent toxic oil products, said Dr Stanley Rice, the manager of the habitat assessment and marine chemistry programme at the Alaska Fisheries Science Center. "Two-stroke engines use oil in the gas mixture as the lubricant for the cylinder walls, and leak a little bit of this out with each stroke," Dr Rice said. "One machine is no big deal, but many add up, over time. The heavier the use, the more of a problem."

In the US, two-stroke engines are banned from lakes used as water reservoirs and in national parks.

In the UAE, there are no regulations on the issue, said Nasser al Shaiba, the director of environment affairs at the Tourism Development and Investment Company (TDIC). While an outright ban may not be possible, authorities should consider phasing out the polluting technology, Mr al Shaiba said.

The unburned oil contains polycyclic aromatic compounds, which even at very low concentrations could damage the embryos of invertebrates, aquatic plants and fish, he said. The problem was that it may take years for people to become aware of the damage. Many embryos would not die at the time of exposure. They would "continue to develop, but fail at later stages.

"Big acute events [such as large oil spills] are easy to see - oil everywhere, dead birds, things like that. But the low-level contaminants do not kill things outright in quantities that you see."

Rather, "they just do not replace themselves as effectively as in the past, and after a few reproductive cycles, there just are not as many as there used to be. And then they are gone."