During the past 20 years, investors have steadily increased their exposure to this factor, so that on average, more than 20% of the equity portion of all retirement accounts could be affected.

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Lack of exposure at auction may be one factor.

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One common factor is that each of them has high European exposure.

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"Based on what we know thus far, I think we have to assume that the No.1 risk factor we have is the degree or extent of exposure, " Bailes said.

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The primary risk factor for human infection appears to be direct or indirect exposure to infected live or dead poultry or contaminated environments.

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The sponsors loved the exposure, TV companies thrived on the novelty factor, the fans enjoyed something different and the drivers approved of the street circuit, which even allowed for overtaking.

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Their study of more than 7, 000 people suggests exposure to bleach and other chemicals is a factor in one in six cases of adult-onset asthma among British people in their mid-50s .

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Another factor that boosts LM Ericsson in Christy's eyes is its substantial exposure to emerging markets, which are also avid consumers of wireless services.

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Vitamin D levels, which play a role in the body's immune response and vary with exposure to sunlight, make latitude of residence a possible risk factor.

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Ironically, because past research studying the after-effects of exposure to things like atom bombs and radiation treatments for cancer suggests the most important environmental risk factor for meningiomas is ionising radiation.

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