Cambior Inc.: Update on the Westwood Project's Drilling Program.

LONGUEUIL, Quebec -- Cambior Inc. (TSX:CBJ)(AMEX:CBJ)

The Deep Drilling Program Continues To Generate Positive Results On The North Corridor And The Westwood Horizon

The most significant results include:

Westwood Horizon
- 2.7 g Au/t and 0.21% Cu over 9.2 metres
- 3.2 g Au/t and 0.27% Cu over 2.1 metres
- 2.0 g Au/t over 4.0 metres

North Corridor
- 10.6 g Au/t over 3.0 metres in a wider interval of low grade
- 4.2 g Au/t and 0.20 % Cu over 1.8 metre

The deep drilling program at the Westwood project, located 2 kilometres east of the Doyon mine, continues to generate positive results. The second deep surface hole (1159 & 1159A) was completed in mid-July to a linear depth of 2,636 metres, or 2,150 metres of vertical depth. This drill hole intercepted the Westwood horizon and the North Corridor which had both been previously intercepted by the other drill holes completed to date. The geological context is similar to that described in previous press releases.

The Westwood horizon was intersected between a depth of 2,308 metres and 2,429 metres (a vertical depth of approximately 2,050 metres), or more than 250 metres deeper than the deepest intersection obtained from wedge 1158EF previously completed and reported in an early press release. This horizon is comprised of numerous mineralized sections, irregularly sericitized, chloritized or biotized, with the presence of garnet. Mineralization is in the form of disseminated to semi-massive sulfides composed of pyrite, pyrrhotite with lesser quantities of chalcopyrite and local sphalerite.

The North Corridor was intersected between a depth of 2,429 metres and 2,529 metres (a vertical depth of approximately 2,100 metres), nearly 500 metres below the deepest intersection obtained by wedge 1158EF. This corridor is characterized by intermediate and mafic volcanics, locally sericitized and mineralized with disseminated sulfides, and intersected by quartz veinlets.

The detailed results from this drilling program are attached to this press release. A detailed longitudinal section for the Westwood project is also attached.

To date, the program carried out from the surface holes has identified a major system of alteration and mineralization associated with the two intersected mineralized corridors and extending over more than 800 metres along the plunge axis and over 350 metres laterally. This mineralized system is similar to those associated with the massive or semi-massive sulphide deposits of the Bousquet and LaRonde mines. It remains open for exploration. In addition, a final wedge (wedge # 5) is underway from main hole 1158 and should permit the association of the mineralized corridors with the older hole 1017- 90 in which two mineralized zones were previously intersected. The exploration program will continue with underground drilling from the exploration drift driven from level 14 of the Doyon mine.

Quality Control

Follow up on the drilling program was carried out by Cambior employees, under the supervision Ms. Marie-France Bugnon, Geologist, M.Sc. Manager, Exploration-Canada. Ms. Bugnon is a qualified person (as defined by National Instrument 43-101) employed by Cambior for more than 8 years and with more than 25 years of experience in exploration. The assay samples came from core halves varying in length from 0.5 to 1.5 metre. They were sent for assaying at Techni-Lab S.G.B. Abitibi Inc. laboratory of Ste-Germaine Boule, Quebec. The samples were assayed by fire-assay followed by atomic absorption or gravimetry, according to industry standards. Repeats on the coarse rejects were carried out on all mineralized intersections of interest and on the majority of the samples containing 1 g Au/t or more. These repeats were duplicated by the laboratory and verified by a second independent laboratory, Intertek Testing Services of Val d'Or, and corroborated the results.

The map mentioned in the text is attached to this press release. If you did not receive it, you can download the map with this press release from the Cambior website, www.cambior.com, or you can contact us at the number indicated at the end of this release.

Cambior Inc. is an international gold producer with operations, development projects and exploration activities throughout the Americas. Cambior's shares trade on the Toronto (TSX) and American (AMEX) stock exchanges under the symbol "CBJ". Cambior's warrant trades on the TSX.

Caution Concerning Forward-Looking Statements

This press release contains certain "forward-looking statements", including, but not limited to, statements concerning the current drilling program, the continuing development plan and the type of mineralization present. Forward-looking statements involve a number of risks and uncertainties. There can be no assurance that such statements will prove to be accurate. Actual results and future events could differ materially from those anticipated in such statements. Risks and uncertainties that could cause results or future events to differ materially from current expectations expressed or implied by the forward-looking statements include, among other things, but without limitation, those set forth in Cambior's 2003 Annual Information Form filed with the Securities Commissions of all provinces in Canada, and with the United Stated Securities and Exchange Commission, as well as the Toronto Stock Exchange and the American Stock Exchange.

Significant Assay Results Au-Ag-Cu-Zn
                        (Drill hole1159A-04)
----------------------------------------------------------------------
-
   Interval        Length    Au  Ag   Cu   Zn
      (m)            (m)   (g/t)(g/t) (%)  (%)   Geological
Description
----------------------------------------------------------------------
-
Beginning of Westwood Horizon (South Side)
----------------------------------------------------------------------
-
2,332.5 - 2,335.5     3    1.2   0.5  0.14%        Sericitized dacitic
                 (2.6 t.t.)                        tuff, garnet, 5-10%
                                                   Py(Cp) with
                                                   veinlets of locally
                                                   massive Py-Cp+/-Qz
----------------------------------------------------------------------
-
2,355.75 - 2,366.5  10.75  2.7   3.0  0.21%        Sericitized dacitic
                 (9.2 t.t.)                        lapilli tuff,
10-20%
                                                   Py(Cp) with
veinlets
                                                   of locally massive
                                                   Py-Cp(Po)+/-Qz
     including
2,356.75 - 2,357.6   0.85  9.6   7.7  0.79%        Qz-biotite vein
                                                   mineralized over
                                                   60cm with
                                                   10-20% Py-Cp
----------------------------------------------------------------------
-
2,374.0 - 2,376.5     2.5  3.2   5.0  0.27%        Mineralized and
                 (2.1 t.t.)                        altered schist
zone
                                                  (green micas)
                                                   With bands of
                                                   semi-massive
                                                   Py and Cp
     including
2,374.0 - 2,375.0     1.0  5.8   6.5  0.38%        Idem
----------------------------------------------------------------------
-
2,403.5 - 2,405.0     1.5  0.5   9.0  0.21% 0.11%  Qz-biotite
veinlets
                                                   with 5-10%
Cp-Po(Sp)
----------------------------------------------------------------------
-
2,411.3 - 2,416.0     4.7  2.0   3.8               Sericitized
horizon
                 (4.0 t.t.)                        with 5-20% Py,
some
                                                   cm thick bands of
                                                   locally massive Py
    including
2,412.5 - 2,413.5     1.0  4.5   7.6               3 cm band of

massive Py(Cp)
----------------------------------------------------------------------
-
2,418.0 - 2,419.0     1.0  1.8   7.7  0.17%        Band of
semi-massive
                                                   Py(Cp)
----------------------------------------------------------------------
-
End of Westwood Horizon- Beginning of North Corridor

----------------------------------------------------------------------
-
2,441.0 - 2,451.0   10.0  5.8(i) 2.5               Strongly biotized
                  (7.5 t.t.)                       magnetic section
                                                   with veinlet/band
                                                   concentrations of
                                                   dispersed Py
     including
2,447.0 - 2,451.0    4.0  10.6(i) 2.5              5-10% mm to cm
                  (3.0 t.t.)                       thick veinlets
                                                   of massive Py
----------------------------------------------------------------------
-
2,485.4 - 2,487.0     1.6  1.5   1.4               Sericitized band,
                                                   garnets, 5-20% Py
----------------------------------------------------------------------
-
2,527.2 - 2,529.0     1.8  4.2   9.7  0.20%        Qz vein enriched
                                                   section, vein wall
                                                   mineralized with
                                                   3-5% Py(Cp-Po)
                                                   disseminated and
                                                   in deformed
veinlets
     including
2,528.0 - 2,529.0     1.0  6.2  11.0   0.18%       Idem
----------------------------------------------------------------------
-
2,591.4 - 2,592.25   0.85  5.3   7.6               Sericitized band,
                                                   3-5% Py fine and
                                                   in clusters
----------------------------------------------------------------------
-
(i) Cutoff grade of 34 g Au/t (one sample had 112.9 g Au/t
    over 1.0 m)

Note :   This table lists only the results greater than 1 g Au/t.
         The lengths are generally the length of the core except
         where indicated as true thickness (t.t).

A map of the Doyon Mine - Westwood Project is available on CCNMatthews' website at the following address : http://www2.ccnmatthews.com/database/fax/2000/cbj0824.pdf