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A new study based on long-term statistical data has provided incontrovertible proof of the link between lung cancer in men and air pollution in the Haifa Bay region.

But the study, which will be published this month, does not suggest a link between the area's pollution and other forms of cancer.

The research is a joint venture by scientists from the Technion, the Health Ministry, Haifa University and Rambam Medical Center. Dr. Micha Barchana, head of the Health Ministry's national cancer registry, was also involved. It is based on data from 1,452 cancer patients diagnosed in 1995-1999 in the Haifa Bay region, which the study defines as the area bordered by Haifa, Nesher, Kiryat Ata and Kiryat Bialik, with a population of 473,300 people and 10 large industrial plants.

The data was crossed-checked against figures for PM10 particles that were measured in Haifa Bay's atmosphere during the same period. The particles - which are smaller than 10 microns, meaning small enough to be inhaled into the respiratory system - constitute an acceptable scientific measure for air pollution.

The research also examined the level of exposure to sulfur dioxide in Haifa Bay, as this is a standard measure for the level of industrial pollution in the air.

The researchers found no link between exposure to sulfur dioxide and any of the cancer types examined in the study. They also found no definitive link between pollution and lung cancer among the area's female residents.

However, they did find a link between exposure to PM10 particles and lung cancer in men: Every one-unit increase in these particles, where a unit is defined as one milligram per cubic meter, raised the risk of lung cancer in bay-area men by 12 percent.

This is the first study that has shown a statistical link between a specific form of cancer and air pollution in Haifa Bay. However, it did not analyze the effect of individual industries on the area's level of air pollution.

According to Health Ministry data, the number of people diagnosed with cancer in Haifa Bay over the last decade is 22 percent higher than the national average for men and 23 percent higher for women. In 2005, there were 377 cancer cases per 100,000 residents in the Haifa Bay area, compared to 355 per 100,000 in Tel Aviv, 348 in Be'er Sheva and 326 in Acre.

Breast cancer rates are 20 percent higher than the national average in the Haifa area, while colon cancer rates are 16 to 25 percent higher than the national average.

But perhaps the starkest figure in the Health Ministry data is the rate of lung cancer among men - which was 52 percent higher in the Haifa Bay region in 2005 than it was nationwide.

Research published in February also found a higher-than-average number of cases of asthmatic children in the Haifa Bay area. According to that study, the rate in the Haifa Bay area is twice as high as those in other parts of the country. The asthma researchers postulated that this high incidence is linked to the cocktail of pollutants emitted into the atmosphere by bay-area industries, but that theory has yet to be proven through research.

Another study, published in July 2009, indicated a possible link between non-Hodgkin's lymphomas and living near busy roadways. However, the relationship was not definitive.

The conclusions of the current research may have legal repercussions, as similar studies around the world have resulted in lawsuits against polluters.

The researchers, however, were quick to qualify their conclusions. Prof. David Broday, who heads the Environmental Exposure and Risk Assessment Laboratory at the Technion, said "the research collected data on several hundred people. By comparison, similar research in the United States examined thousands of cases. This has implications for the statistical clarity of the findings."

Moreover, he said, "Israel's registry of cancer patients does not have data on patients' smoking habits, and it is possible that smoking is another factor in the high rates of cancer in Haifa Bay."

But according to Health Ministry data, 25.5 percent of Jewish men in the Haifa Bay region smoke, compared to 28.6 percent in the Upper Galilee and the Golan, 32.5 percent in the Jerusalem district and 33.1 percent in the south. Among Arab men, the rate of smokers in Haifa Bay is 33.9 percent, which is similarly low compared to rates of 47.8 percent in the south, 49.1 percent in the Jerusalem area and 60 percent in the Tel Aviv-Jaffa region.