You can easily find info about changes and who and when changed the lock of enviromnent
select CHD_ID AS [Change_Id]
, CHD_CFCID [Changed_object_code]
,case when CHD_OldValue = 0 then 'Unblocked' when CHD_OldValue = 1 then 'Blocked' end as [Old_value]
,case when CHD_NewValue = 0 then 'Unblocked' when CHD_NewValue = 1 then 'Blocked' end as [New_value]
, CHR_TSInsert as [Date of change]
, CHR_RowID as [Row change]
, CHO_CreatedBy as [Who changed]
from ChangeDetails
join ChangeRows
on CHD_CHRID = CHR_ID
join ChangeOperations
on CHR_CHOID = cho_id
and CHO_ObjectID = 142 --column with value of changes
where CHD_CFCID = 1507 --attribute Environment blocking