ASSESSMENT OF THE RADIOLOGICAL IMPACT OF PHOSPHATE
MINING AND MANUFACTURING IN EGYPT
Principal Investigator
AbdcI-A/.iz El - Dakhakhny, Ph.D.
High Institute of Public Health
University of Alexandria
Project Officer
Sam J. Windham
Eastern Environmental Radiation Facility
Montgomery, Alabama 36109
U. S. Environmental Protection Agency University of Alexandria
1982
-------
Assessment of the
Mining and
Radiological Impact of Phosphate
Manufacturing in Egypt
Principal Investigator
Abdel-Aziz El-Dakhakhny, Ph.D.
High Institute of Public Health
University of Alexandria
Project Officer
Sam J. Windham
Eastern Environmental Radiation Facility
Montgomery, Alabama 36109
U.S. Environmental Protection Agency University of Alexandria
U.S. Environmental Protection
Library, Room 2401 PM-211-A
401 M Street, S.W.
Washington, DC 20460
Agefloy
1982
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TA8LE OF CONTENTS
Page
FORWARD
LIST OF FIGURES
LIST OF TABLES
INTRODUCTION 1
A. Relationship of Phosphates and Environmental 1
Relation
B. Phosphate Areas in Egypt 1
C. Egyptian Phosphate Mining Processes 3
D. Potential Health Impacts of Mining Processes 3
SCOPE OF THE STUDY 3
A, Goals 5
B. Study Sites 6
1. Sibaeiah . 6
2. Quseir 8
3. Hamrawein 9
4. Safaga 11
METHODOLOGY 11
A. Radon Concentration 11
B. Radon Daughter Concentration and Working Level 12
C. Gamma Ray Levels 12
D. Radioassay Procedures Xi-
1. Uranium-Thorium • • 12
2. Radium 12
RESULTS 13
SUMMARY AND CONCLUSIONS * 20
RECOMMENDATIONS 21
REFERENCES 22
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LIST OF FIGURES
Page
1. Phosphate Mining Areas in Egypt 2
2. The Sibaeiah Site 7
3. The Hamrawein Site 10
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LIST OF TABLES
Page
1. Sampling Results - Sibaeiah 14
2. Sampling Results - Safaga 15
3. Sampling Results - Hamrawein 16
4. Sampling Results - Quseir 17
5. Sampling Results - Radium, Uranium, Thorium 18
Concentrations, All Sites
6. Ore Concentrations and Ventilation Types for Mines ... 19
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FORWARD
This study has been conducted by Dr. Abdel-Aziz El-Dakhakhny, Ph.D.
Professor of Occupational Health Engineering, Department of Occupational
Health, High Institute of Public Health, University of Alexandria, Egypt.
The study was supported under TA-3-546-2, sponsered by the U.S. Environ-
mental Protection Agency.
The author wishes to gratefully accknowledge the assistance of
U.S. EPA' Sam Windham, Richard Guimond, Jennings Partridge and Ellery
Savage for their contributions to the execution of the study and pre-
paration of the report. The author also wishes to acknowledoe the
efforts of Dr. Ali Helil, Ph.D. and Sabri S. Ali, M.S. and the Phosphate
Mining Companies for their cooperation : El-Nasr for Phosphate, Misr Co.
for Phosphate, and the Red Sea Co. for Phosphate.
The author also wishes to thank the Staff of the Department of
Occupational Health for their support and help in fulfilling the work,
also thanks are due to Mr. Mounir Abdel-Malek for typing this manuscript.
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I. INTRODUCTION
A. Relationship of Phosphates and Environmental Radiation
Phosphate ores throughout the world contain significant
concentrations of uranium and its decay products. The literature
indicates that the concentration of uranium and radium in Egyptian
phosphate samples is about 120 ppm and 40 pCi per gram, respectively
(Me68). These concentrations are similar to phosphate ores in the
United States (Gu75). Studies by the U.S. Environmental Protection
Agency (USEPA) have shown that because of the high uranium and radium
concentrations in these ores, a large amount of radioactive material
can be redistributed within the environment through products, by-
products, wastes, effluents, and emission (G»>75). In addition,
occupational radiation exposures, particularly to underground phosphate
miners may be significant.
B. Phosphate Areas in Eqyp :
Phosphate ores are mined in two regions within Egypt, the Red
Sea area and the Nile Valley area of Upper Egypt (Fig. 1). Some mines
utilize underground and strip mining techniques to extract the phosphate
ores while others employ only underground techniques. Most of total
production, however, is produced by underground mining, which mostly
employ natural ventilation. Therefore, there is an obvious potential
for the build-up of radon decay product concentrations in the under-
ground mine environments.
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Ki/r
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(J) : Phosphate Mining Areas in Egypt.
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C. Egyptian Phosphate Mining Processes
The phosphate industry in Fgypt is quite varied. In some inst-
ances the phosphate ore is brought to the surface, crushed on-site and
the crushed ore is .r;»nsported by barge (down the Nile) to fertilizer
processing plants. In other instances the ore is transported by rail
to crushers and processing plants, and in still other instances, mining,
crushing and processing may all occur at one location. All the phosphate
mined in Sibaeiah is shipped to fertilizer plants in Egypt where it is
processed to normal superphosphate and used domestically. The mines in
the Red Sea area produce ore totally for exportation.
Plans are under study to bring the production rate to 10 million
tons of phosphate per year from the huge deposits of phosphates in the
Abo Tartour area. Progress is currently underway to greatly increase
the production of phosphate or;? at other mines over the next few years.
In addition, benification facilities will be constructed to improve the
phosphate (P^Q^) concentration of the marketable ores. These benificat-
ior plants will either store the slifi'e tailings in large ponds or dis-
charge them directly to irrigation drains or tc the Nile River.
D• Potential Health Impacts of Mining Processes
The phosphate industry in Egypt employs greater than ten thousand
workers. Further, a number of the facilities-; are located near towns and
cities where dust and other atmospheric emissions may result in exposures
to nearby residents.
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A previous study performed by the High Institute of Public
Health suggested that radiation levels in underground phosphate mines
may greatly exceed levels recommended by the International Commission
of Radiation Protection as well as radiation protection standards adop-
ted in countries such as the United States (Aw61). This information
coupled with data from environmental studies performed in the United
States regarding the radiolonical impact of the phosphate industry
suggest that exposures to the public and workers may warrant control
measures to minimize the risk of any adverse health impact to these
people. The adverse health impact of greatest concern is an increased
incidence of lung cancer due to the inhalation of radon daughter decay
products.
For the purposes of radiological protection of the lungs, the
U.S. Secretary of Labor promulgated the following standard in 1968 :
"Occupational exposure to radon daughters in mines shall be controlled
so that no individual will receive any exposure of more than two WLM
in any consecutive 3 month period and no more than four WLM in any con-
secutive 12 month period. Actual exposures shall be kept as far bplow
these values as practicable".
(a) Working level (WL) is defined as the quantity of radon daughter
products which will deposit 1.3 x 10^ Mev of energy in 1 liter of
air, or, 100 pCi/1 of radon in equilibrium with its daughters.
A working level month (WLM) results from exposure to 1 WL for a
period of 140 hrs.
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The above two standards are considered the operational guide
lines for exposure of miners to radon daughters. Exposure to rad-
iation other than the inhalation of radon daughters must be considered
separately. The usual occupational safe limit is 5 rem/year for whole
body external exposure. As a limit for radon gas, the International
Commission on Radiological Protection recommends that the occupational
exposure to radon and daughter products (MPC ) should be 30 pCi/1.
II. SCOPE OF THE STUDY
A. Goals
The study was designed to establish a data base of radon and
radon daughter concentrations in selected Egyptian mine atmospheres.
From this data base, the radiological impact of phosphate mining in
Egypt will be evaluated. The measurements made to build this data
base include : radium, uranium and thorium concentrations in ores;
working levels; radon concentrations inmine atmospheres, and gamma
ray exposure rates.
The measurements were performed at four phosphate mining areas
Sibaeiah, Hamrawein, Safaga and Quseir. Details of these study sites
are provided later in this report.
Measurements were made starting in January 1979 and were conc-
luded in September 1980.
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In some cases, each mining site is actually composed of several
individual mine shafts. Sampling occurred in individual shafts and
various levels within each shaft as follows :
Hamrawein - 4 shafts, total of 4 levels
Safaga - 3 shafts, 1 level in each
Quseir - 4 shafts, 1 level in each
Sibaeiah - 4 shafts, a total of 5 levels.
B. The Study Sites
1. Sebaeiah
This mine is located between Idfu and Isna, 5 km from the Nile
River in the eastern range. During the time of study, the main mining
operations have taken place in the following sites as shown in Fig. 2.
El-Manasig opencast and underground
El-Yamania opencast
Ewiniah N. & S. opencast and underground
Mahamid E. 4 S. underground
New project underground
The ore is mostly tricalcium phosphate. The ore strata thickness
varied from 0.6 to 2.5 m. Tricalcium phosphate constitutes about 56 - 65
percent of the ore.
In open pit mining, holes are made by pneumatic dry drilling filled
with dynamite and blasted. The ore is taken manually and is carried by
cars to the main collection site in Sibaeiah.
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In underground mining, the mines are not deep. The ore strata
are nearly levelled and are found to be 5 - 30 meters deep. The strata
are overlaid mostly by a thin solid chart ceiling. The phosphate ore
is mined by blasting and is hand loaded in rail cars driven by miners or
by small locomotives and is brought to the surface; then it is carried
by cars to the crusher plant in Sibaeiah where the ore is crushed and
sieved to the required size. The final ore production is stored in big
heaps ready for transportation by the railway and by barge to the super-
phosphate fertilizer plants in Assiut and Kafr El-Zayat.
The mining operations were found to be very dusty. They do not
utilize any mechanical means to remove dust or to change air. They depend
completely on natural ventilation.
This survey was conducted during May 1979 and January 1980. Measure-
ments were taken in different mining sites which were El-Yamen, Winch S.,
Mine 314, Ewiniah S., Mahamid E, and Mahamid W.
2. Quseir
This mine is located near Quseir which is a small port on the Red
Sea. The mine is old and it has been in operation since 1916.
The main production areas are s
Gabal :
1. Dowy (El-Beida)
2. Old Quseir
3. Yonis A <5c B
4. Abu Shigela project
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The ore is tricalcium phosphate. The ore strata are not levelled
and are inclined 20° to the horizontal. The mines are very deep where
the environment is hot and humid, but not dusty except during drilling
operations, they depend mainly on natural ventilation. The ore is
brought to the surface by a bucket elevator through an inclined shaft.
All the ore produced from the different mining sites are transported by
railway to Quseir. After crushing and sieving the ore is totally pre-
pared for exportation.
The survey was conducted during May 1980. Measurements were taken
at different mining sites which were Gabal Dowy level 27 N, old Que
level 6 N., Yonis level 1 E and Abu Shigela project level 4.
3. Hamrawein
This mine is located between Quseir and Safaga in the Red Sea area.
The mine was opened quite recently. The mining operations are taken place
in sites A, B, C, D, E and F which are located in Wadi Hamrawein, Abu
Hamra and Queh as shown in Fig. 3.
The ore strata thickness range between .80 - 2.0 m and are included
about 17° ore ran9es between 20 - 30 %. Most of the mines
are deep. They employ rubber conveying belts and some mechanical means
to bring the ore out of the mines. Also they employ mechanical ventilation
to remove dust and to bring fresh air. The ore is loaded in rail cars
driven by locomotives to the calcination plant in Hamrawein where it is
prepared for exportation.
The survey was conducted during January, February, May and October
1979. Measurements were taken at different mining sites which were
mine A, B, D and H.
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HAMRAWEIN MINES
SCALE 1:1 00000
Fig. (3) : The Hamrawein Site
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4. Safaqa
The ruining area is located in the Red Sea area north nf Hamrawetn
and Quseir. The nines are old and have been in operation for many years.
Safaga mines resemble Quseir mines in that they are deep and employ room
and pillar method to get the ore. The mining operations takes place in
mines 305, .51)6, Shedwan, .507, 7 and Naser which are located in Was:.if
and 0m El-Hewitat areas. The ore is transported by railway to the crusher
in Safaga, and prepared totally for exportation.
The survey was conducted during September 1980 and measurements
were taken at different mining sites which were mines Shedwan, 7 and 507.
HI. METHODOLOGY
The general methodology employed in this study was identical for
each mine site and is described below.
A. Radon Concentration
Grab samples of air within each mine were collected in evacuated
125 ml scintillation cells (Randam Inc., Cincinnati, Ohio, U.S.A.} from
various locations within the mine. The number of samples collected varied
according to the size and characteristics of each mine. Details of the
number of samples collected are presented in the Results Section. The
purpose of the sampling protocol was to establish the average or character-
istic conditions of each mine to which the miners were exposed. These
samples were allowed to equilibrate for approximately three hours and were
then counted on Randam Model SC-5 scintillation counters. Observed count
rates were corrected for radioactive decay according to established methods
(Wi76) and radon concentrations in pCi/liter calculated.
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B. Radon-Daughter Concentration and Working Level
Air samples from various locations within each mine site were
drawn through 47 mm membrane filters (0.8 micron pore size) using battery-
powered gast air pumps at the rate of 6 to 10 1/min for 5 minutes. These
air filters were then counted on Ludlum Model 43-1 scintillation detectors
at 5, 15, and 30 minutes following sampling. Radon daughter concentrations
were calculated using the modified Tsivoglou Technique (Ma69). This
technique yields both radon daughter concentrations and ultimately, working
level.
C. Gamma-Ray Levels
Gamma exposure rates were determined, with Ludlum Model 12-S port-
able scintillation survey instruments which had been calibrated with a
Reuter-Stokes Model RS-111 pressurized ionization chamber. Readings were
recorded in micro-Roentgens per hour.
D. Radio-Assay Procedures
1. Uranium-Thorium
The concentrations of uranium and thorium isotopes in the phosphate
ores were determined using the techniques employed by USEPA's Eastern
Environmental Radiation Facility (EERF) in Montgomery, Alabama. Basically,
this technique involves chemical separation and alpha spectroscopy (Gu75).
2. Radium
Radium-226 concentrations in solids were determined by gamma analysis.
Samples to be analyzed were dried and ground to a uniform consistency.
Eight grams of the prepared sample were sealed in a 7.5 ml glass vial and
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allowed to equilibrate for 28 days. Following this period the entire
vial was counted in a sodium iodide well crystal and the radium cal-
culated based on the intensity of the bismuth-214 peak. For calibration,
identical vials were sealed containing dried sand on which had been
placed a know quantity of radium-226 nnd allowed to equilibrate. Blanks
containing dried sand but no radium were counted for back-ground sub-
traction.
IV. RESULTS
Sampling results are shown in Tables 1-6. Tables 1 - A list
radon concentrations (pCi/1) working levels (WL), and gamma measurements
(uR/hr) for the Sibaeiah, Safaga, Hamrawein and Quseir mining sites
respectively. Data are presented for several individual mines and for
some mines, individual levels within each shaft for each mining site.
Table 5 summarizes the results of radiochemical analyses performed
on ore samples from all of the four mining sites.
Working level values are reported as calculated using the method
described earlier (Ma69). Radon concentrations are reported as calc-
ulated from counting data (Wi76), and rounded to the nearest whole pCi/1.
Gamma exposure rate measurements are reported as ranges of scintillation
survey meter readings observed by the surveyors. Radiochemical analyses
are reported as calculated from sample counting data.
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Table (1) : Sampling Results - El-Sibaeiah (WL, Rn, and Gamma)
Working Level Radon Con. pCi/1 Gamma
Mine Date g g level
Range Ave. Range Ave. UiR/hr)
El-Yamen
May
79
0.016-0.19
0.09+0.09
3 -
15
7
+
4
70
Jan
80
0.052-0.47
0.23+0.21
9 -
78a
33
+
35
40
- 45
Southern Winch
May
79
0.086-0.21
0.16+0.155
18 -
87
47
+
22
42
- 45
Jan
80
0.18 -0.38
0.23+0.06
40 -
76
57
+
16
40
Mine 14
May
79
0.101-0.44
0.28+0.14
8 -
117
48
+
31
65
- 90
Mahamid West 1
Jan
80
0.11 -0.36
0.2 +0.07
18 -
37
26
+
9
35
- 38
East
Jan
80
0.21 -0.57
0.37+0.13
33 -
62
50
+
10
30
- 35
a : Two measurements were made in close proximity to face of mining location and had radon concentrations of
77 and 78 pCi/1. Omitting these two, the range would be 9 - 13 pCi/1 with an average of 11 + 2 pCi/1.
b : Averages are reported with a + 1 standard deviation of the mean error term.
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Table (2) : Sampling Results - Safaga (WL. Rn, and Gamma)
Mine
Date
Working Level
Range
Ave.
Wassif area
Shedwan mine
Sept 80
3.86-3.97 3.9+.05
0m El-Howitat
Mine 7 level 4
Sept 80
1.46-1.57 1.52+.08
Wassif area
North Winch
level 307
Sept 80
0.76-1.14 0.92+.17
B : See footnote b, table 1.
Radon Cone. (pCi/1) Gamma
r- level
Range Ave. (uR/Hr)
401-452 429+24 80
96-168 160+50 70-80
117-170 148+20 35-40
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Table (3) : Sampling Results - Hamrawein (WL, Rn, and Gamma)
Mine
Date
Working level
Range
Ave.
Mine A
Jan
79
.065-.16
.112+.048
Oct
79
1.41 -2.13
1.8+.25
Mine B
Feb
79
0.02 -.038
.029+.013
Oct
79
.085 -.315
.15 +.093
Mine D
Jan
79
.006 -.01
.008+. 002
Oct
79
.137 -.306
.22 +.07
Mine H
Feb
79
0.047
0.047
Oct
79
.01 -.203
.052+.063
Mine H
Oct
79
.063 -.167
.108+.037
level 622
3 North
Oct
79
.032 -.065
.047+.017
b : See footnote b, table 1.
Radon Cone. (pCi/1)
Range Ave.'*
Gamma
level
(uR/Hr)
4 - 133 66+46 90-100
230 - 425 333+58
2 - 26 10+7 40 - 60
24 - 64 46+15
10 - 21 13+3 100
45 - 198 106+48
5 - 22 14+7 60 - 80
12 - 121 61+31
3-14 10+3
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Table (4) : Sampling Results - Quseir (WL, Rn, and Gamma)
Mine Date
Working Level
Range Ave.*3
Quesir Old May 80 .095-.125 0.11+.01
Mine 6 north
Yonis A May 80 .057-.44 0.17+.18
Level 1 east
Abu Shegelah May 80 >031-.053 0.042+.02
Gabal Dowy May 80 -
Level 27 north
b : See footnote b, table 1.
Radon Cone. (pCi/1)
"T I b~
Range Ave.
31 - 39
15 - 30
9-13
28 - 41
35 + 3
24 + 5
11 + 2
37 + 5
Gamma
level
(uR/Hr)
50
45
30 - 40
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Table (5) : Sampling Results
Radium, Uranium, Thorium Concentrations, All Sites (pCi/g)
Uranium Thorium
Mine Radium
226 234 235 238 227 228 230 232
Hamrawein 31.6 31.9 2.1 29.9 2.4 0.8 33.0 0.74
Sibaeiah 17.3 19.4 1.57 19.6 2.2 0.85 17.6 0.70
Safaga 19.2 20.9 1.8 22.6 1.4 1.5 20.4 2.1
Quseir 11.8 12.6 0.9 12.1 1.2 0.45 12.0 0.4
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Table(6): Radium Ore Concentrations, Ventillation Types and
Depths for Mines.
Mine/Shafts
Average (pCi/g)
radium ore
concentration
Type of
ventilation
Mine
depth
Sibaeiah
El-Yamen
18.7
Southern winch
17.4
Mine 14
19.7
Mahameed
West 1
14.8
Mahameed
East
16.2
Safaqa
Wasif area
Shedwin mine
21.2
Aum El-Howitat
Mine 7 level 4
18.0
Wasif area
North winch
level 307
21.7
Hamrawe in
Mine A
29. 1
Mine B
18.4
Mine D
31.6
Mine H
22.8
Mine H
level 622
22. 1
Matural Shallow
ventilation mine
(5-15 meters)
Mechanical
ventilation
Medium
mine
( 30 meters)
Cont.
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19'
Table 6 (Cont.)
Average (pCi/g) Type Mine
Mine/Shafts radium ore ventilation depth
concentrat ion
Quseir
Quseir old
mine 6 north
Yonis A
level 1 east
Abu Shegalah
14.4
11-4 Natura1 Deep
14.0
ventilation mines
( 100 meters)
Gabel Dowy
level 27 north
9.2
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V. SUMMARY AND CONCLUSIONS
An examination of the data presented in tables 1-6 supports
four main conclusions :
(a) Even within a single mining area, there is great variability
between measurements from individual shafts. This is due to such
factors as, whether the shaft is actively mined or abandoned; how
deep in the mine the samples were taken; the existence and/or type
of ventilation employed, and the relative concentrations of radium-226
in the ores being mined.
(b) At all four mining areas, measurements of working level and radon-222
were found which exceed existing occupational exposure guidance,
some by as much as a factor of 10 or more.
(c) No gamma exposure levels were found which exceed the 5 R/year whole
body exposure limit. The highest reading observed when projected
over a 2000 hour working year would only result in 0.2 R annual
exposure. This value is approximately 5 times the average gamma
background exposure rate for the area (6-8 uR/hr.).
(d) It appears from the data that the use of a mechanical ventilation
system in the mine shafts exerts a great influence on the working
levels present. An examination of data from the Hamrawein area,
for example, shows that the average working levels encountered
there are the lowest of the four sites studied, even though the
concentration of radium-226 in the ore and the accompanying radon
concentrations are the highest measured.
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VI. RECOMMENDATIONS
Based on our findings in this study, four recommendations present
themselves :
1. The beneficial effects of ventilation in reducing sub-surface
radon daughter levels is obvious and supported by the work of other
investigators. It seems judicious, therefore, to recommend that
all new sub-surface phosphate mines be fitted with positive ventil-
ation systems. Further, existing mines exhibiting elevated working
levels (Sibaeiah and Safaga) should be considered for retrofitting
with positive ventilation systems if this option is economically
feasible.
2. It is probable that workers in at least some of these mines have
been exposed to radon and radon daughter levels sufficiently high
enough to increase the incidence of health effects. This suggests
that follow-up epidemiological studies of these workers, along with
monitoring of their overall future health might prove informative
and useful.
3. No environmental sampling was conducted in the immediate vicinity
of these mines. Based on the levels found in the mines, environ-
mental measurements should be made and any potential health effects
to persons living close to the mines should be projected.
4. Other sub-surface mining activities in Egypt should be evaluated
in terms of their potential for similar cond^ions and studied if
necessary.
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REFERENCES
Me68 Menzel, R.G. 1968 : "Uranium, Radium, and Thorium Content in
Phosphate Rocks and Their Possible Radiation Hazards". J. Org.
Food Chem. 16, 2.
Gu75 Guimond, R.J. and Windham, S.T. 1975 : "Radioactivity Distribution
in Phosphate Products, By-Products, Effluents, and Wastes".
U.S. Environmental Protection Agency. Tech. Rep. ORP-CSD-73-3.
Aw61 Awwad, H., El-Sherbibi, A.F., Hammoud, E., Hazaa, I., Kharadly, M.,
and Valic, F. 1961 : "Radiation Hazards in Red Sea Phosphate
Mines". J. Egypt. Publ. H. Assoc. 36, 1.
Ma69 Marty, D.E., Holleman, D.F., McCurdy, D.E. and Schiager, K.J. 1969 :
"Analysis of Atmospheric Concentrations of RaA, RaB, and RaC by
Alpha Spectroscopy". Health Phys. 17.
Wi76 Windham, S.T., Partridge, J.E. and Horton, T.R. 1976 : "Radiation
Dose Estimates to Phosphate Industry Personnel". U.S.EPA-520/5-
76-014.
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