WASHINGTON (CNN) -- The Justice Department official who last year issued a blistering report on the FBI's crime laboratory said Thursday the FBI has made most, but not all, of the changes he recommended.

In a report released by the Justice Department, Inspector General Michael Bromwich said the FBI has adopted many new policies, practices and protocols recommended in his report, but called for internal and external reviews to make sure the new guidelines are followed in practice.

Bromwich also said he believes the FBI has more work to do.

"We have noted some specific areas of continuing concern, and the FBI's commitment to correct them. However, on the whole we believe that the FBI has done a sound and responsible job of implementing the recommendations," Bromwich wrote.

Top FBI officials readily admitted to serious problems in the explosives unit, the materials analysis unit and the chemistry-toxicology unit after the harsh, 517-page report issued by the inspector general on April 15, 1997.

Bromwich said he still has concerns about restructuring and preventing contamination in the explosives unit, the drafting of lab reports, laboratory training and the lack of qualified scientists in the explosives unit.