Journal of Environmental Protection, 2011, 2, 221-230
doi:10.4236/jep.2011.23026 Published Online May 2011 (
Copyright © 2011 SciRes. JEP
Agrochemicals and the Ghanaian Environment, a
Joseph R. Fianko1,4, Augustine Donkor2, Samuel T. Lowor3, Philip O. Yeboah4
1Department of Chemistry, NNRI/GAEC, Legon, Accra; 2Department of Chemistry, University of Ghana, Legon, Accra; 3Cocoa
Research Institute of Ghana, Akim Tafo; 4School of Nuclear and Allied Sciences, University of Ghana, Legon, Accra.
Received August 18th, 2010; revised Janaury 17th, 2011; accepted February 22nd, 2011.
Agrochemicals are generally recognized as a significant factor in enhancing the ability to meet Ghanas need for suffi-
cient, safe and affordable food and fiber, however, increased usage have led to environmental deterioration. In Ghana
agriculture and public health sectors remain the major contributors of pollutants into the environment. This is a sys-
tematic review of studies done in Ghana to give an integrated picture of agrochemicals especially pesticides exposure
to humans, animals, plants, water, soil/sediment and atmosphere in Ghana. Although the widespread usage of agro-
chemicals in Ghana has contributed immensely to increased food supply and improvement in public health, it has
caused tremendous harm to the environment. Water bodies, fish, vegetables, food, soil and sediment have been found to
be pesticide contaminated. There is considerable evidence that farmers have overused agrochemicals especially pesti-
cides. It is evident from biological monitoring studies that farmers are at higher risk for acute and chronic health ef-
fects associated with pesticides due to occupational exposure. Furthermore the intensive use of pesticides involves a
special risk of for field workers, consumers and unacceptable residue levels in exportable products may serve as bar-
rier to international trade. This review will set the future course of action of different studies on agrochemical usage
and pesticide exposure in Ghana.
Keywords: Ghana, Agrochemicals, Environment, Pollution, Exposure
1. Introduction
Agrochemicals are integral part of current agriculture
production systems around the world. Accordingly, the
use of agrochemicals viz fertilizers and pesticides remain
a common practice particularly in many nations in the
tropical world [1]. Pesticides like 1,1,1-trichloro-2,2-bis
(4-chlorophenyl) ethane (DDT) and 1,2,3,4,5,6-hexa-
chlorocyclohexane (HCH) which are environmentally
persistent prohibited from use in developed nations con-
tinue to be most widely used pesticides in developing
countries including Ghana because they are cheap, easy
to synthesis or they are given by developed nations.
Many pressure groups, example, Consumer Associations,
Non-governmental Organizations and International bod-
ies are against the presence of these persistent pesticides
in the environment. They perceive the presence of pesti-
cide residues in the environment as detrimental to human
health and water quality.
The contamination of the environment and exposure of
the public to pesticide residues in food could lead to high
health risk. Results of scientific research reveal that even
in low concentrations, the combined effect of persistent
synthetic chemicals such as pesticides causes suppression
of immune response and hypersensitivity to chemical
agents. Causes of breast cancer, reduced sperm count,
male sterility etc are well documented as a result of pes-
ticide ingestion [1]. Death cases and pesticide poisoning
have been reported around the world particularly in de-
veloping countries [2]. In Ghana, agrochemicals used in
farming dates back to the colonial era and have been in-
herent component in agricultural practices in the nation.
The objective of this review is to summarize the agro-
chemical monitoring studies in Ghana and gives the true
picture of their detrimental effects to the environment. It
will also determine the current state of knowledge in ag-
rochemicals in Ghana to set the future plan of action in
agrochemical research in Ghana.
2. Agro-Chemical Use in Crops in Ghana
Agriculture is the most important sector in Ghana’s
economy, forming nearly 41% of total Gross Domestic
Product (GDP) [3]. Out of the total area of 238.854
Agrochemicals and the Ghanaian Environment, a Review
square kilometers of Ghana only 57% (13 628 000 hec-
tares) is suitable for agriculture. However, 6 331 000
hectares of the arable land are cultivated because the soils
are infertile and only productive with proper management
and good agricultural practice [4,5]. In the light of these
and the need to increase food supply, the use of crop
protection chemicals, organic fertilizers, improved water
and soil management as well as increased area of agri-
culture land seems the simplest way to obtain better yield.
Instead, the current trend has been the decrease of agri-
culture land (hectares per inhabitant) in all regions of the
globe as a result of population growth, net loss of agri-
cultural land due to erosion, reduction of fertility, salini-
zation and desertification of soils [1]. Therefore the best
response to the need for increasing food production is
more intensive use of agrochemicals.
As farms have become massive in size, the challenges
in keeping the crop free of damage have increased.
Hand-tilling weeds have become impractical, as one
example. Thus the whole world has known a continuous
growth of agrochemical usage both in numbers and
quantities. The use of agrochemicals has been critically
important in increasing the yield of agricultural crops.
However, some uses of agrochemicals cause environ-
mental and ecological damage, which detracts signifi-
cantly from the benefits gained by the use of these mate-
rials. The most commonly used fertilizers are inorganic
compounds of nitrogen (N), Phosphorus (P) and potas-
sium (K).
In Ghana, agro-chemicals are used in cocoa, oil palm,
cola nut, coffee and cotton farms, vegetable (e.g. tomato,
eggplant, onion, pepper, okra, cabbage, lettuce, carrot)
and fruit production (e.g. papaya, citrus, avocado, mango,
cashew, pineapple), mixed-crop farming systems involv-
ing cereals (e.g. maize, millet, sorghum, rice), tuber crops
(e.g. yam, cassava, cocoyam, sweet potato) and legumes
(e.g. cowpea, bambara nut, groundnut, soybean). Overall,
agrochemical especially fertilizer use on pineapple is
fairly high because pineapple is grown on sandy soils.
3. Fertilizer Use in Ghana
The use of chemical fertilizers has increased tremen-
dously worldwide since the 1960s and is largely respon-
sible for the green “revolution” i.e. the massive increase
in production obtained from the same surface of land
with the help of mineral fertilizers (nitrogen, phosphorus,
potassium) and intensive irrigation [1]. At present, Ghana
does not manufactured fertilizers; all fertilizers used in
Ghana are imported [1]. The major importers of fertilizers
into Ghana are private companies, Agricultural Devel-
opment Bank and some commercial farms. The most
important imported products are compound fertilizers
Ammonium Sulphate (AS) and Muriate of Potash (MOP)
with urea, Single Super Phosphate (SSP) and Triple Su-
per Phosphate (TSP) being minor imports (Table 1) [3].
Compound fertilizers accounted for 48 percent of the
total amount of fertilizers consumed in Ghana between
1995 and 2003 with nitrogenous fertilizers (urea and
ammonium sulphate) accounting for 30 percent of the
total fertilizers consumed. The consumption of fertilizers
fell substantially in the early 1980s because of adverse
economic conditions; nonetheless, it increased in the
second half of the 1990s following an improvement in
the national economy, ever since it has been steady (Ta-
ble 2). The Upper East and the Upper West Regions are
Table 1. Fertilizer imports into Ghana (“000 tonnes”).
Year N.P.K (15-15-15) Other Compounds Urea MOP AS SSP/TSP & others Total
1997 19.2 17.9 1.9 5.5 10.7 1.1 56.3
1998 13.1 8.8 0.5 3.1 13.3 3.6 42.4
1999 3.2 0.4 0 8.1 4.8 5.5 22.0
2000 14.1 0.8 0.1 4.5 23.2 0.8 43.5
2001 31.8 17.5 2.5 4.1 22.6 2.3 80.8
Table 2. Mean fertilizer consumption by region in Ghana.
1997 1998 1999 2000 2001
Region (tonnes)
Ashanti 5167 3893 2023 4046 7438
Brong Ahafo 7582 5712 2969 5937 10,914
Central 1629 1229 638 1275 2345
Eastern 1011 762 396 792 1455
Greater Accra 1236 931 484 967 1779
Northern 15,220 11,467 5960 11,917 21,910
Upper Regions 15,501 11,679 6070 12,137 22,314
Volta 8481 6390 3321 6640 12,208
Western 337 254 132 264 483
Total 56,164 42,317 16,593 43,975 80,846
Source: [4,5]
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Agrochemicals and the Ghanaian Environment, a Review223
the largest fertilizer consumers in Ghana. The Upper East
Region has two large irrigation schemes at Tono and Vea.
Because of the high economic value of tomatoes and
onions during the dry season, farmers regularly tend to
apply more fertilizers to these crops, hence the increased
volume of fertilizers usage in the Northern sector.
Pesticide Use in Ghana: Ghana is a developing coun-
try experiencing high economic growth rate in the West
African Sub-region [3]. As an agriculture-based nation,
the use of pesticides contributes much to the national
development and public health programmes. Ever since
the inception of pesticides, its use to protect crops from
pests has significantly reduced losses and improved the
yield of crops such as cereals, vegetables, fruits and other
crops. Ghana thus, has known a continuous growth of
pesticide usage, both in number of chemicals and quanti-
ties because of the expansion of area under cultivation for
food, vegetables and cash crops [4].
Pesticide application in Ghana is more concentrated in
cocoa, oil palm, cereals, vegetables and fruits sectors.
Although purchased physical inputs (agrochemicals,
seeds and tools) represent less than 30% of the total cost
of crop production, the use of pesticides is becoming
more widespread. For instance, between 1995 and 2000,
about 21 different kinds of pesticides were imported into
the country for agricultural purposes [5]. Its use has been
embraced by local communities that are making a living
from sale of vegetables and other cash crops. There is
ample evidence that this products especially tomatoes are
always sprayed and sold immediately after maturity for
consumption. This inevitably puts a high risk on con-
sumers who always get their supply directly from the
farmers. In Ghana, it is estimated that 87% of farmers
who use pesticides, apply any of the following or a com-
bination of pyrethroids, organophosphates, carbamates,
organochlorines on vegetables [6].
Among the different types of pesticides known, or-
ganochlorine pesticides are the most popular and exten-
sively used by farmers due to their cost effectiveness and
broad spectrum activity. Lindane was widely used in
Ghana on cocoa plantations, vegetable farms, and for the
control of stem borers in maize [7]. Endosulfan is popu-
larly applied in cotton growing areas, vegetables farms,
and coffee plantations [5] in some parts Ghana. Pesti-
cides particularly DDT and lindane which are no longer
registered for any use in the country were once employed
to control ecto-parasites of farm animals and pets in
Ghana [8].
Pesticides mostly used to control foliar pests of pine-
apple in Ghana include chlorpyrifos, dimethoate, diazi-
non, cymethoate and fenitrothion while the fungicides
maneb, carbendazim, imazil, copper hydroxide are used
for post-harvest treatment [9,10]. Lambda-cyhalothrin,
cypermethrin, dimethoate and endosulfan are also used
by vegetable growers in tomato, pepper, okra, egg-plant,
cabbage and lettuce farms. Glyphosate, fluazifop-butyl,
ametryne, diuron or bromacil are normally employed in
land clearing [11]. Nonetheless, the most extensively
used pesticides in the pepper, tomato, groundnut and
beans cultivation are karate, cymbush, thiodine, diathane,
lubillite and kocide [12].
Dinham [13] estimates that 87% of farmers in Ghana
use chemical pesticides to control pests and diseases on
vegetables and fruits. Ntow et al. [8] gave the propor-
tions of pesticides used popularly on vegetable farms as
herbicides (44%), fungicides (23%) and insecticides
(33%). In a study encompassing 30 organized farms and
110 kraals distributed throughout the 10 regions of
Ghana, Awumbila and Bokuma [14] found that 20 dif-
ferent pesticides were in use with the organochlorine
lindane being the most widely distributed and used pesti-
cides, accounting for 35% of those applied on farms. Of
the 20 pesticides, 45% were organophosphorous, 30%
were pyrethroids, 15% were carbamates and 10% were
organochlorines [14].
In the public health sector, pesticides, primarily te-
mephos have been used by the Onchocerciasis Pro-
gramme in the Volta Basin for the control of black flies
(Simulium spp. Diptera: Simulidae), which transmit
Onchecerciasis (African river blindness, a disease caused
by the pathogenic nematode, Onchocerca volvulus) to
humans and for the control of diseases [15] and domestic
pests, such as cockroaches, various flies, mosquitoes,
ecto-parasites including ticks and other insects [16]. Pes-
ticides have also been used to control black flies along
the banks of the Tano and Pra rivers [17].
Analysis of pesticide trade flow patterns, recorded by
Ghana’s Statistical Service, in 1993 indicated that a total
of 3,854,126 kg of pesticides were imported with the
following distribution and use as per Figure 1 [18]. Be-
sides, a survey conducted between 1992 and 1994 in the
Ashanti, Brong Ahafo, Eastern and Western Regions of
Ghana revealed that the most broadly used pesticides by
farmers are: copper(II) hydroxide (29.0%), mancozeb
(11.0%), fenitrothion (6.0%), dimethoate (11.0%), pirimi-
phos methyl (11.0%), λ-cyhalothrin (22.0%), and endo-
sulfan (10.0%) [19]. Moreover, it was established that
insecticides constituted about 67% of pesticides em-
ployed by farmers while fungicides were about 30% and
herbicides and other pesticides types form 3% of the total
On the other hand, it is on record that between 1995
and 2000, an average of 814 tons of pesticides was im-
ported into the country annually, the greatest quantity
being insecticides, 70% [5]. The amount of pesticides
imported into the country from 2002 to 2006 increased
Copyright © 2011 SciRes. JEP
Agrochemicals and the Ghanaian Environment, a Review
from 7763 metric tonnes to 27,886 metric tonnes, (Table
3). Updated register of pesticides from the Environ-
mental Protection Agency in Ghana in 2008 indicated
that about 141 different types of pesticide products have
been registered in the country under the Part II of the
Environmental Protection Agency Act, 1994 (Act 490).
These consists of insecticides (41.84%), fungicides
(16.31%), herbicides (0.43%) and others (0.01%) [20].
4. Pesticides in Surface and Ground Water
A fundamental contributor to the “Green Revolution” has
been the development and application pesticides for the
control of a wide variety of pests that would otherwise
diminish the quantity and quality of food produce [2].
Notwithstanding the increased food production, massive
use of pesticides has caused serious contamination of
aquifers and surface water bodies, decreasing the quality
of water for human consumption [1,21]. Pesticide resi-
dues have been a catch cry of environmental and con-
sumer groups since the mid-1960’s when Rachel Carson
[22] drew the public’s attention to the deleterious eco-
logical effects of organochlorine pesticides especially
1,1,1-trichloro-2,2-bis-(4’-chlorophenyl) ethane (DDT),
which were in widespread use at that time.
Water samples from rivers in the intensive cocoa
growing areas in the Ashanti and Eastern Regions of
Ghana have been found to contain lindane and endosul-
fan [23]. Water samples from Akumadan, a vegetable
farming community in the Ashanti Region and different
areas of Ghana revealed the presence of significant levels
of pesticide residues (Table 4). The Volta Lake was also
found to be mildly contaminated with lindane, DDT,
DDE and endosulfan [17]. In Oda, Kowire and Atwetwe
rivers in Ghana, mean pesticide concentrations found in
water samples for lindane and endosulfan were 19.4 and
12.4 µg·L1 (Oda), 16.4 and 17.9 µg·L1 (Kowire) 20.5
and 21.4 µg·L1 (Atwetwe), respectively [23].
Figure 1. Distribution of pesticides imported into Ghana in
Table 3. Annual imported pesticides into Ghana from 2002
to 2006.
Metric Tonnes
Class of Pesticide
20022003 2004 2005 2006
Insecticides 41305974 8418 10,00612,728
Herbicides 2186 2939 4578 856610718
Fungicides 1079 1249 2402 2205 3195
Others 368 496 544 707 1224
Total 776310,658 15,942 21,484 27,886
Table 4. Pesticides detected in water samples from different areas of Ghana.
Area Detected Concentration(µg·L1) Freq. of detection Reference
Lindane 9.5 76 [24]
α-endosulfan 62.3 64
β-endosulfan 31.4 60
Endosulfan sulfate 30.8 78
Lindane 0.008 22.8 [17]
α-endosulfan 0.036 15.6
β-endosulfan 0.024 17.8
Endosulfan sulfate 0.023 10.6
Volta Lake
Lindane 0.071 [24]
Endosulfan 0.064
DDE 0.061 82
Bosomtwi Lake
DDT 0.012 78
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Agrochemicals and the Ghanaian Environment, a Review225
5. Pesticides in Food
Effects of pesticides have been reported in milk, vegeta-
bles, fruits, meat, fish meal and other food at different
intervals in the country. Analysis of street-vended food
samples in Accra, between 1999-2000 revealed disturb-
ing levels of contamination by pesticides, heavy metals,
microorganisms and mycotoxins [23]. The pesticide
chlorpyrifos was detected in six out of eight samples of
waakye (rice and beans) and one out of eight samples of
fufu (cassava and plantain dough). Vegetables on the
Ghanaian market were found to contain detectable levels
of chlopyrifos, lindane, endosulfan, lambda-cyhalothrin,
and DDT residues in lettuce, cabbage, tomato and onion
Significant amount of different pesticides have been
reported for other foods besides that in vegetables and
fruits (Table 5). The possible reason for pesticides to
Table 5. Pesticide residues in different foods in Ghana.
Area Commodity Detected Concentration (µg·kg1) Reference
Kumasi abattoir Beef fat Lindane 4.04 [24]
endosulfan 21.35
Aldrin 2.06
DDE 118.45
DDT 545.24
dieldrin 5.25
Beef Lindane 2.07
endosulfan 1.88
Aldrin 1.43
DDE 42.93
DDT 18.83
dieldrin 5.92
Buoho abattoir Beef fat Lindane 1.79
endosulfan 2.28
Aldrin 4.11
DDE 31.89
DDT 403.82
dieldrin 6.01
Beef Lindane 0.60
endosulfan 0.59
Aldrin 0.73
DDE 5.86
DDT 10.82
dieldrin 11.48
Kumasi Cheese DDE 31.50
Yoghourt DDT 42.17
milk DDT 12.53
Endosulfan sulfate 10.6
Bosomtwi Lake fish Lindane 0.126
Endosulfan 0.713
DDE 5.23
DDT 3.64
Aldrin 0.018
dieldrin 0.035
Kumasi Vegetables Chlorpyrifos-methyl 94.0
Chlorpyrifos 153.5
Dichlorvos 86.5
Dimethoate 117.5
Malathion 209
Monocrotophos 61.5
Omethioate 61
Parathion methyl 31
parathion 71
Kumasi Lettuce Lindane 300 [25]
Lambda Cyhalothrin 500
DDT 400
Chlorpyrifos 1600
Endosulfan 400
Copyright © 2011 SciRes. JEP
Agrochemicals and the Ghanaian Environment, a Review
reach these aquatic environments is through direct runoff,
leaching, careless disposal of empty containers, equip-
ment washing etc which is evident from literature [2].
Studies on pesticide residues in exportable quality cocoa
beans collected from selected cocoa growing districts in
the middle belt of Ghana and the two shipping ports at
Tema and Takoradi also showed detectable amount of
lindane residues; the average level was about 10% of the
maximum residue level of 0.1 µg/g permitted by Codex
Alimentarius Commission [27]. Nonetheless, many other
studies conducted so far have revealed the presence of
detectable levels of pesticides especially organochlorines
in fruits, vegetables, fish and fish products [12,27,28].
The studies pointed out that majority of the samples
contaminated by chlorinated pesticides exceeded the
maximum residue limits which could cause pesticide
hazard to the consumer.
6. Pesticides in Soils and Sediments
The natural processes that govern that fate and transport
of agrochemicals especially pesticides in the environ-
ment can be grouped into the broad categories of runoff,
leaching, sorption, volatilization, degradation and plant
uptake [29]. Once applied to soil, a number of things
may happen to an agrochemical [30]. It may be taken up
by plants or ingested by animals, insects, worms, or mi-
croorganisms in the soil. It may move downward in the
soil and either adheres to particles or dissolve. The pesti-
cide may vaporize and enter the atmosphere, degrade via
solar energy or break down via microbial and chemical
pathways into other less toxic compounds. Pesticides
may leach out of the root zone or wash off the surface of
land by rain or irrigation water, eventually ending in the
sediments through the water column. Evaporation of
water at the ground surface can lead to upward flow of
water and pesticide [30].
The fate of pesticides applied to soil depends largely
on two of its properties: persistence and sorption [1,2,29].
Two other pathways of pesticide loss are removal in the
harvested plant and volatilization into the atmosphere,
which subsequently impact water, sediment, soil, and air
quality negatively and creating problems for agricultural
workers who could be pesticide intoxicated via inhala-
tion at the treated areas. The sources of all these con-
tamination are the consequences of human activities like
domestic, industrial discharges, agricultural chemical
application and soil erosion due to deforestation. Ac-
cordingly, high concentrations of pesticide residues in
harvested produce could have ecological health impacts
on consumers. However, in the case of fish subsequent
accumulation in biota could occur through bioaccumula-
tion and biomagnifications through different trophic lev-
els in the aquatic food chain.
Studies in Ghana [17,24,31,32] have reported the de-
tection of different kinds of pesticides especially or-
ganochlorines in soil and sediment in different parts of
Ghana (Table 6). The fate of propoxur residues in cocoa
ecosystem studied revealed that no residue of propoxur
could be detected after 21 days after spraying [33].
Glover-Amengor et al., [31] and Nuertey et al., [32]
Table 6. Pesticides detected in soils/sediments in Ghana.
Area Detected Concentration (µg·kg1) Frequency of Detection (%) Reference
Lindane 3.20 95.2 [6]
α-endosulfan 0.19 95
β-endosulfan 0.13 88
Endosulfan Sulfate 0.23 97
HCB 0.90 90.5
Heptachlor 0.63 97.6
Akomadan (Soil)
DDE 0.46 88.1
Lindane 2.30 91.7 [17]
α-endosulfan 0.21 86.1
β-endosulfan 0.17 88.9
Endosulfan Sulfate 0.36 94.4
P,p-DDT 9.00 22.2
Volta Lake (Sediment)
P,p’-DDE 52.30 97.2
Lindane 6.76 [24]
Endosulfan 9.68
DDE 8.34 98
DDT 4.41
Aldrin 0.065
Bosomtwi Lake (sediment)
Dieldrin 0.072
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Agrochemicals and the Ghanaian Environment, a Review227
measured the effect of excessive use of pesticides on
biomass and microorganisms in oil palm and vegetable
agro-ecosystems. They observed that the pesticides in-
hibit bacterial population resulting in inhibited nitrifica-
tion and blockage of other soil microorganisms of both
organic and inorganic constituents in the soil, hence de-
creasing the soil fertility. Yield of vegetables notably
garden eggs and tomato were suppressed by increased
application of lindane. Pesticide application had a higher
effect on fungal population.
Studies of the solubility of pesticides and its sorption
on soil are known to be inversely related, increased solu-
bility implies less sorption. One of the most useful indi-
ces for quantifying pesticide sorption on soils is the par-
tition coefficient (Koc) defined as the ratio of pesticide
concentration in the sorbed-state (bound to soil particles)
to solution-phase (dissolved in the soil-water). Thus, for
a given amount of pesticide applied, the smaller the Koc
value, the greater the concentration of pesticide in solu-
tion. Pesticides with small Koc values are more likely to
be leached compared to those with large Koc values [34].
Studies on depletion of herbicides in two soil ecosystems
in Ghana [35] indicated that the kinetics involved in the
process of depletion of the herbicides to a higher degree
could be described as first order reaction kinetics and the
half-life of herbicides ranged between 14.8 and 32.2 days.
Apoh et al., [36] in their study of the persistence of lin-
dane in Ghanaian coastal savanna topsoil reported that
the dissipation pattern favours second order kinetics and
persistence depend on the organic matter content of the
Sunlight induced reactions may contribute to the
chemical transformation of organic pollutants. Recent
evidence [29,30] suggests that organic pollutants may
react through both direct and indirect photochemical
pathways. Many river basins are eutrophic and contain
higher amounts of dissolved organic matter (DOM). In
connection with these, studies of both DOM and nitrate
was shown to the degradation of pesticides by sunlight.
Moisture and organic matter content was found to facili-
tate depletion of herbicides in soils [31,35,36]. The de-
gree to which this could occur may highly depend upon
the composition and amount of photosensitizers present.
Most of the dissolved organic matter in natural waters is
comprised of decomposed organic matter and extracellu-
lar products as well as amorphous humic substances
which may contain a variety of chromophoric functional
groups that absorb sunlight.
7. Pesticides and Human Health Impacts
Pesticides have improved longevity and the quality of
life, chiefly in the area of public health. The use of pesti-
cides also constitutes an important aspect of modern ag-
riculture. Unfortunately, most pesticides are poisons and
can be particularly dangerous when misused. Fish-kills,
reproductive failure in birds, and acute illnesses in peo-
ple have all been attributed to exposure to or ingestion of
pesticides, usually as a result of misapplication or care-
less disposal of unused pesticides and containers. Pesti-
cide losses from areas of application and contamination
of non-target sites such as surface and ground water rep-
resent a monetary loss to the farmer as well as a threat to
the environment [1].
Meeting the minimum requirements of occupational
health standards is regarded as one of the elements of
sustainable agricultural development. In Ghana, there are
no countrywide statistics on the extent of poisoning of
farmers through pesticide. Three reasons have been iden-
tified for this: 1) farmers seek medical attention only in
cases of serious health problems due to the costs in-
volved 2) most of the farmers are not aware of the spe-
cific symptoms of pesticide poisoning and 3) health
workers are not informed and therefore cannot draw the
right conclusions, and the system of health statistics does
not clearly specify cases of poisoning.
While epidemiological studies have often implicated
agrochemicals especially pesticides as causative agents
in human cancer, it has usually been at a marginal level
of significance. It is suspected that DDT and its metabo-
lite DDE, still persisted in the environment long after
being banned and may be involved in the causation of
breast cancer as a result of estrogenic activity [16].
Human exposure to pesticides in Ghana may be exces-
sive, especially through ground application in cocoa,
pineapple, cotton and vegetable farms where compounds
of high toxicity are often used [33,38]. Large number of
workers, labourers, and spraying observers are involved
in spraying of these farms but unfortunately, they are
often not equipped with protective clothes or masks.
Therefore, this may reflect the great magnitude of human
exposure to pesticide intoxication in Ghana. Official re-
ports on agro-chemical poisoning are lacking, except a
few published reports [2,5,8]. A survey on the extent of
pesticide associated symptoms in farmers involved in
irrigation projects in Ghana revealed that about 36% of
the farmers had experienced negative side effects after
applying pesticides [16]. The most significant symptoms
include headache, dizziness, fever, blurred vision, and
nausea/vomiting. A study on farmer’s perception and use
of pesticides in Ghana [8] also revealed that although
some farmers may be aware of pesticide hazards, ade-
quate protection is hardly taken to minimize risk while
knowledge of pesticide selection, application rates and
timing are also poor.
A study on possible poisoning caused by pesticides was
carried out by researchers of the Ghana Standards Board
Copyright © 2011 SciRes. JEP
Agrochemicals and the Ghanaian Environment, a Review
and the Department of Pathology of the University of
Ghana between 1989 and 1997 [37]. The research ana-
lyzed organs of the body, body fluids, foods and drinks
submitted by various hospitals and other state institutions
in Ghana. Out of the 1215 toxicological cases examined,
963 tested positive for chemical poisoning. The 30%
cases of chemical poisoning were directly related to the
misuse of pesticides. The main causes for deaths were
carbamates (126 cases), organophosphorous (66 cases)
and organochlorines (74 cases). Unfortunately in March
1999, three children died after consuming fruits contain-
ing high residue of carbamates [5] in Ghana.
An epidemiological survey and haematological studies
on the probable effect of pesticide on the health status of
farmers in Akomadan and Afrancho traditional area of the
Ashanti Region of Ghana conducted by Mensah et al. [38],
revealed that most of the farmers have experienced
sneezing (56%), skin irritation (65.9%), headaches (48.2%),
dizziness (40.0%), abdominal pains (20.0%) and cough
(57.6%). About 30% of the farmers were found to have
low red blood cells (RBC) and 38% low white blood cells
(WBC). Yeboah et al., [39] reported cases of fatal occu-
pational poisoning recorded by the Plant Protection and
Regulatory Services of the ministry of Agriculture in
Ghana (PPRS) between 1986 and 1989.
Further investigation into probable effects of aerosol
pesticides on hepatic functions among farmers in Ako-
madan and Afrancho districts in the Ashanti region [12]
indicated that aerosol pesticides used by farmers did not
pose any immediate threat to hepatic function of farmers
at least in short term, however, long term effect of per-
sistent pesticide usage could not be overlooked. Mercury
from mercuric pesticide has been known to cause poi-
sonings in areas where seed grains were treated with
mercuric pesticides to curb fungal growth. These occur-
rences have exhibited toxic effects in humans and wild-
life [40] in Ghana. Feeding birds are also susceptible to
adverse effects of mercuric pesticide coated grains and
several species have experienced reduced reproduction
and increased mortality. Thus, the unfortunate conse-
quences of pesticide use has led to wildlife distress, in-
terference with reproduction, birth defects, and depressed
immunity which detrimentally affects wildlife popula-
tions and on a larger scale the surrounding ecosystem.
8. Pesticides in Air and Human Exposure
In Ghana, the chances of misuse of agrochemicals are
relatively high due to low awareness of the safe use of
agrochemicals especially pesticides and illiteracy. There
are various means by which human become exposed to
agrochemicals and other toxic chemicals, notable among
which are exposure via diet, drinking water, soil and air.
Persistent pesticides move through air, soil, and water
finding their way into living tissues where they can bio-
accumulate up the food chain. The public health risks of
pesticides depend not only on how toxic various com-
pounds are, but also on how many people are exposed,
their risk-related demographic, socioeconomic and health
profile, the kinds of contaminants they are exposed to,
and the extent and routes of exposure. The general popu-
lation can be exposed to low levels of pesticides in three
general ways: vector control for public health and other
non-agricultural purposes; environmental residues; and
food residues.
Health and safety issues are exacerbated by a general
lack of hazard awareness; the lack of protective clothing,
or difficulty of wearing protective clothing in tropical
climates; shortage of facilities for washing after use, or
in case of accidents; the value of containers for re-use in
storing food and drink; illiteracy; labeling difficulties
relating either to language, complexity or misleading
information; lack of regulatory authorities; and lack of
enforcement. Poisoning surveillance systems are usually
maintained only at large urban hospitals. Village health
centers may be completely excluded from monitoring
reports [16].
A study by Yeboah et al., [12] and Mensah et al., [38],
revealed that about 82% of farmers in Ghana are illiter-
ates and do not always use any form of standard protec-
tive clothing. Most of the farmers were not aware of long
term chemical and physiological effect associated with
improper agrochemical handling. About 41.5% of farm-
ers claim they change their cloths before and after pesti-
cide use, however, less than 5% washed these clothing
before using them again. These contaminated clothing
can enhance dermal exposure which can result in sys-
temic poisoning. It was also revealed that some of the
farmers were involved in unhealthy practices that put
them at high risk of being affected by the pesticides.
They drink from water bodies near their farms and eat
without washing their hand with any detergent.
Malnutrition could bring about an increased suscepti-
bility to pesticide intoxication, especially in women and
children. Malnourishment, infectious diseases, and toxic
chemicals interact with each other and with the immune
system. Consequently, pesticides immunosuppressive
effects which have more pronounced health consequences
in developing countries, could significantly affect im-
mune responses at very low doses. Humans ingesting food
preparations contaminated with pesticide, workers in
pesticide manufacturing and packing units, and agricul-
tural workers who prepare, mix, and apply pesticides in
the fields are all potentially exposed to more than one
pesticide on the same or on successive days. Such expo-
sure may induce a wide array of health effect, ranging
from myelotoxicity to cytogenetic changes and carcino-
Copyright © 2011 SciRes. JEP
Agrochemicals and the Ghanaian Environment, a Review229
genic effects.
Human exposure is on more sporadic basis through a
hodgepodge of human activities, farmers and farm
workers; workers and laborers in pesticide factories;
populations that live in areas of intensive pesticide use or
production; and populations exposed to persistent pesti-
cides that bioaccumulate in food are potentially exposed
to pesticide hazards [12]. Those that can be exposed to
high levels of bio-accumulated pesticides include: con-
sumers of fish, livestock, and dairy products; foetus and
nursing infants whose mother’s bodies have accumulated
substantial levels of persistent agrochemicals; and sick
people who metabolize pesticide-bioaccumulated fatty
tissues while ill [38]. Soil can be a key source of expo-
sure in young children who show significant hand-to-
mouth activity. Although modern pesticides are readily
degraded in the environment by soil micro-organisms,
residues on treated crops such as fruit or vegetables often
do not dissipate quickly. Most pesticides lack systemic
action and therefore residues are mainly on the exterior
surfaces where they are amenable to removal in opera-
tions such as trimming, washing or peeling that most
crops undergo before consumption.
9. Conclusions
Agrochemicals are generally recognized as a significant
factor in enhancing the ability to meet Ghana’s need for
sufficient, safe and affordable food and fiber, however,
increased usage have led to environmental deterioration.
The review of agrochemical monitoring and exposure
clearly indicate that not much have been done in the area
of agrochemical studies in Ghana. There was lack or
absence of corrective and preventive measures, presence
of persistent, bioaccumulative and toxic agrochemicals in
water, fish, vegetables and human fluids and there is
strong evidence that accidents of pesticide exposure in
Ghana may occur due to lack of awareness about safe
use of agrochemicals. Keeping in view of the present
scenario, it is strongly recommended that extensive
awareness creation for safe use of agrochemicals be in-
troduced, epidemiological studies and impact of agro-
chemical usage in the country be instituted. This will
provide information on biological indices of agrochemi-
cals for effective monitoring of exposure of farmers and
farm workers to agrochemicals.
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