Firms with payrolls or employment levels below a certain threshold, which would include the vast majority of small businesses, would be exempt from the pay-or-play provisions.

WHITEHOUSE: THE WHITE HOUSE

The findings suggested that the plants' NOx emissions could result in a 35% increase in the number of days when ozone levels exceeded the upper threshold set by the US Environment Protection Agency.

BBC: Invasive plant 'increases ozone pollution'

If your adjusted gross income next year is lower than the threshold for the additional Medicare tax levels, your capital gains rate for 2013 might only be 20% (and it could even remain at 15%, depending on how the new rules end up after negotiations).

FORBES: Sell Stock by Year-end for Tax Reasons? Think Twice

Where levels over the 1% threshold are confirmed, the FSA will publish details as soon as this information is received.

BBC: Further tests after 'horse DNA' find in beef products

Meanwhile, HSBC's preliminary or "flash" reading of China manufacturing Purchasing Managers' Index showed Monday that activity improved in April from levels seen in March, but remained below the threshold of 50, indicating a contraction.

WSJ: Asia Stocks Fall on China Data

Even though his PSA levels were still below the 4.0 nanograms per milliliter threshold considered to be a positive PSA score, Stephen, who asked that we only use his first name, said he just wanted to eliminate the cancer risk.

CNN: Let men decide on prostate screening, cancer society says

After reporting concern about contamination, water quality tests performed by the Texas Railroad Commission found naturally-occurring levels of benzene, a known carcinogen, which exceeded the threshold limit for drinking water, but found no evidence to support a flaming water claim.

FORBES: Promised Land's Fracking Fictions: OPEC Goes Hollywood With Crocudrama

The DoD has already complained that the new levels are not justified by the scientific evidence on dioxin, particularly that there is a threshold under which it is not carcinogenic to humans, and that the EPA has failed to use on the most up-to-date research to formulate its clean up goals.

FORBES: Is The EPA About To Shut Down Urban Renewal Across The U.S.?