Construction’s unemployment rate continued to head downward in August, dipping to 11.3% from July’s 12.3%, but the industry posted a gain of just 1,000 jobs last month.

The Bureau of Labor Statistics’ latest monthly employment status report, released on Sept. 7, also showed that construction’s jobless rate last month was better than the 13.5% level for August 2011.

But industry officials said one factor behind the construction unemployment rate’s decline is that many workers have left the construction industry.

Stephen Sandherr, Associated General Contractors of America CEO, said, “While we all breathe a sigh of relief any time the sector adds jobs, these numbers are hardly cause for celebration.”

Anirban Basu, Associated Builders and Contractors chief economist, said the improved August construction jobless rate “seemed to be a pleasant surprise.” But he added that “under further examination, this is largely due to former construction workers moving to other industries or leaving the workforce….” ACG said that more than 700,000 workers have exited the construction industry since 2009, including 214,000 since August 2011.

Sean McGarvey, president of the AFL-CIO Building and Construction Trades Dept., noted the improvement in the industry’s jobless rate, but added that at 11.3% “it is still disturbingly high for an industry of such importance to our nation’s overall economic health.”

Construction’s August rate was the highest among U.S. industries, according to the BLS report. The leisure/hospitality sector was second-highest, at 10.1%. No other industry had a rate above 8.9%.

The BLS report also showed that the August pickup in construction jobs was concentrated in the residential specialty trade contactors sector, which added 8,200 positions, and heavy-civil engineering, which gained 2,800. The buildings and nonresidential specialty trade contractors segments lost a combined 9,900 jobs in August.

Architectural and engineering services—which BLS separates from the construction category—added 3,800 positions in August.

The overall national unemployment rate declined to 8.1% in August from July’s 8.3%, as the economy added 96,000 jobs. That was well below the 141,000 jobs gained in the previous month.