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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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<SEC-DOCUMENT>0000930413-08-007461.txt : 20081230
<SEC-HEADER>0000930413-08-007461.hdr.sgml : 20081230
<ACCEPTANCE-DATETIME>20081230061622
ACCESSION NUMBER:		0000930413-08-007461
CONFORMED SUBMISSION TYPE:	NSAR-B
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20081031
FILED AS OF DATE:		20081230
DATE AS OF CHANGE:		20081230
EFFECTIVENESS DATE:		20081230

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BlackRock Health Sciences Trust
		CENTRAL INDEX KEY:			0001314966
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE

	FILING VALUES:
		FORM TYPE:		NSAR-B
		SEC ACT:		1940 Act
		SEC FILE NUMBER:	811-21702
		FILM NUMBER:		081274097

	BUSINESS ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809
		BUSINESS PHONE:		(888) 825-2257

	MAIL ADDRESS:	
		STREET 1:		100 BELLEVUE PARKWAY
		CITY:			WILMINGTON
		STATE:			DE
		ZIP:			19809
</SEC-HEADER>
<DOCUMENT>
<TYPE>NSAR-B
<SEQUENCE>1
<FILENAME>c55967_nsarb.fil
<TEXT>
<PAGE>      PAGE  1
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080 B000000 NATIONAL UNION FIRE INSURANCE COMPANY ET AL
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SIGNATURE   DONALD C. BURKE
TITLE       TREASURER

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.77B
<SEQUENCE>2
<FILENAME>c55967_ex99-77b.txt
<TEXT>
REPORT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

To the Trustees and Shareholders of:

BlackRock Dividend Achievers(TM) Trust
BlackRock Enhanced Dividend Achievers(TM) Trust
BlackRock Strategic Dividend Achievers(TM) Trust
BlackRock EcoSolutions Investment Trust
BlackRock Global Energy and Resources Trust
BlackRock Global Equity Income Trust
BlackRock Global Opportunities Equity Trust
BlackRock Health Sciences Trust
BlackRock International Growth and Income Trust
BlackRock Real Asset Equity Trust
BlackRock S&P Quality Rankings Global Equity Managed Trust
BlackRock World Investment Trust
(Collectively the "Trusts")

In planning and performing our audits of the financial statements of the Trusts
as of and for the year ended October 31, 2008, in accordance with the standards
of the Public Company Accounting Oversight Board (United States), we considered
the Trusts' internal control over financial reporting, including control over
safeguarding securities, as a basis for designing our auditing procedures for
the purpose of expressing our opinion on the financial statements and to comply
with the requirements of Form N-SAR, but not for the purpose of expressing an
opinion on the effectiveness of the Trusts' internal control over financial
reporting. Accordingly, we express no such opinion.

The management of the Trusts is responsible for establishing and maintaining
effective internal control over financial reporting. In fulfilling this
responsibility, estimates and judgments by management are required to assess the
expected benefits and related costs of controls. A company's internal control
over financial reporting is a process designed to provide reasonable assurance
regarding the reliability of financial reporting and the preparation of
financial statements for external purposes in accordance with generally accepted
accounting principles. A company's internal control over financial reporting
includes those policies and procedures that (1) pertain to the maintenance of
records that, in reasonable detail, accurately and fairly reflect the
transactions and dispositions of the assets of the company; (2) provide
reasonable assurance that transactions are recorded as necessary to permit
preparation of financial statements in accordance with generally accepted
accounting principles, and that receipts and expenditures of the company are
being made only in accordance with authorizations of management and directors of
the trust; and (3) provide reasonable assurance regarding prevention or timely
detection of unauthorized acquisition, use, or disposition of a company's assets
that could have a material effect on the financial statements.

Because of its inherent limitations, internal control over financial reporting
may not prevent or detect misstatements. Also, projections of any evaluation of
effectiveness to future periods are subject to the risk that controls may become
inadequate because of changes in conditions, or that the degree of compliance
with the policies or procedures may deteriorate.

A deficiency in internal control over financial reporting exists when the design
or operation of a control does not allow management or employees, in the normal
course of performing their assigned functions, to prevent or detect
misstatements on a timely basis. A material weakness is a deficiency, or a
combination of deficiencies, in internal control over financial reporting, such
that there is a reasonable possibility that a material misstatement of the
company's annual or interim financial statements will not be prevented or
detected on a timely basis.

Our consideration of the Trusts' internal control over financial reporting was
for the limited purpose described in the first paragraph and would not
necessarily disclose all deficiencies in internal control that might be material
weaknesses under standards established by the Public Company Accounting
Oversight Board (United States). However, we noted no deficiencies in the
Trust's internal control over financial reporting and its operation, including
controls for safeguarding securities, that we consider to be a material
weakness, as defined above, as of October 31, 2008.

This report is intended solely for the information and use of management and the
Board of Trustees of the Trusts and the Securities and Exchange Commission and
is not intended to be and should not be used by anyone other than these
specified parties.

DELOITTE & TOUCHE LLP

New York, New York

December 26, 2008
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----
