There has been a decline in the number of people dying in Israel from diseases related to air pollution over the past decade, according to new data released by the Environmental Protection Ministry.
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The ministry’s study describes how it believes steps taken at Israeli power plants have significantly improved air quality. It highlights the health benefits associated with power stations in Haifa, Tel Aviv and Ashdod switching to less polluting fuels.
The study, led by Dr. Lital Yinon-Wolf and Prof. George D. Thurston, was conducted at the NYU School of Medicine and the results were published in the scientific journal Environment International.
The main finding is that a change in fuel type led to a 13.3 percent drop in the number of cardiovascular-related deaths associated with exposure to air pollution in the period between 2000 and 2011.
Early in the last decade, the three power plants used a heavy, low-quality fuel oil called Mazut, which contains a lot of sulfur. This led to the emission of high levels of sulfur oxides and other tiny particles that can enter the respiratory system. This type of pollution is known to cause an elevated risk of death from heart or blood vessel disease. The study spanned a period in which mazut was still used and a few years after a new fuel type was introduced.
Following demands by the Environmental Protection Ministry, the three power plants gradually switched to using fuels with lower sulfur content. With the discovery of natural gas in Israeli waters and its increasing supply for generating electricity, the power plants switched to using natural gas instead.
Using new types of fuel reduced the emission of sulfur oxides by more than 70 percent in the three cities studied.
Researchers then examined rates of mortality from diverse causes, including cardiovascular disease, respiratory disease and more. They built a model for assessing how changes in mortality rates were related to air pollution. The model was based on data from other places around the world in which causal connections could be made between exposure to pollution and mortality rates.
“Studies of morbidity caused by air pollution try to assess the link between exposure and health implications,” explained Yinon-Wolf. “In our study we looked for causality, not a statistical connection. Our control was the population prior to the changes that were made.”
The researchers had to rule out other reasons for the decline in deaths. A previous study in Ireland showed a significant decline in deaths from respiratory and cardiovascular disease after coal-burning was prohibited in Dublin. However, it was later shown by comparing the data to other regions that this was due to an overall improvement in health, not to reduced coal-burning.
In the new study, researchers also looked at other regions in Israel, enabling them to dismiss other causes for the decline. Yinon-Wolf stressed that other explanations that were not included in the model may still be possible.
In the study, researchers established that the most significant reduction in mortality rates was due to the switch to low-sulfur fuels. They believe this changed the composition of small polluting particles emitted by the power plants, reducing their toxicity.
“This type of study is important since it analyzes large-scale ‘experiments’ that were carried out as part of new regulations, based on models and assessments. The impact of the new policy could not be measured before it was implemented,” said Prof. David Broday, a pollution researcher at the Technion – Israel Institute of Technology, Haifa.
“It’s important to test this policy after it’s launched to see if it meets expectations and if it is an efficient policy,” Broday continued. “If results are positive, this serves as a yardstick for the quality of decision-making, as well as providing quantitative measures of the improvement in air quality and the attendant health benefits. The study confirms the policy direction and can support further investment by showing good returns, with lower costs of treating potential patients.”
The results are important for the Environmental Protection Ministry, since it is promoting measures to reduce coal-burning and increasing the use of natural gas. The reduced sulfur-emission project will end in 2020, halving the current amount of emissions associated with generating electricity.
The emission-reducing project in coal-burning power plants also includes the introduction of measures to deal with contaminants at the Hadera and Ashkelon sites. Later, some of the older units in Hadera will be decommissioned, with the installation of new units that operate on natural gas. The ministry is worried by delays, though, partly caused by the National Infrastructure, Energy and Water Ministry.
Residents and regional councils in several areas may also hamper the realization of these plans, since they view the use of natural gas as an environmental threat. Areas affected include Gilboa and near Beit She’an (both in northern Israel), and the Sharon area in central Israel.
Last week, meanwhile, Kfar Sava Mayor Zvika Tsarfati appeared before the National Infrastructure Committee, which is examining a potential new power plant near his city, expressing his opposition to the move. “I never hear talk about the residents,” he told the panel. “Where is the consideration for them and their quality of life? We will strenuously oppose this plant – it has no place in Kfar Sava. We understand the need for a new power plant, but it can’t impact residents and future plans for the city.”
Tsarfati argued that the new facility would pollute the air in a region already plagued by environmental hazards, including a waste-burning site, sewage treatment plant and heavy traffic.
“No one wants activity that increases air pollution next to them,” acknowledged Reut Rabi, who is in charge of energy issues at the Environmental Protection Ministry’s air quality division. “Comparatively, though, using natural gas is the least polluting method after renewable energy sources. These stations emit mainly nitrous oxides. Tests we conducted in plants already operating with natural gas have shown the addition of pollutants there is not significant as a health hazard.”
The Health Ministry says short-term exposure to sulfur dioxide only causes minor irritation, but constant exposure can lead to respiratory problems, especially in children. The researchers in the new study say some of the pollutants react in the air to produce particles, which raise the risk of death, although the biological mechanisms are unclear.
One of the central units at the Hadera power plant has been emitting 80 to 90 percent fewer sulfur oxides since a new pollution-reduction system was installed. The emission of nitrous oxide, meanwhile, has dropped by 90 percent. These two pollutants are known to increase morbidity and mortality rates through damage to the respiratory and cardiovascular systems.