Vol.3, No.10, 631-637 (2011)
opyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
Human health and occupational exposure to pesticides
among smallholder farmers in cotton zones of Côte
Oluyede Clifford Ajayi*, Festus Kehinde Akinnifesi, Gudeta Sileshi
World Agroforestry Centre, Nairobi, Kenya; *Corr esponding Author: Ajay i@gmx.net
Received 14 June 2011; revised 13 July 2011; accepted 21 July 2011.
While precautionary efforts are being made to
minimize human health problems associated
with agricultural pesticides, the continued oc-
currence of occupational poisoning from these
chemicals raises major concerns among stake-
holders. Information gap on human health
problems associated with pesticides poses
major obstacles to making informed policy de-
cisions, particularly in developing countries
where most of the poisonings occurs. In this
study, we identified acute human health symp-
toms associated with pesticide use in cotton
zone of Côte d’Ivoire and, documented the re-
sponse of rural households to the symptoms.
The results show that cotton farmers in Cote
d’Ivoire suffer from different occupational
health hazards from exposure to agricultural
pesticides. Key health symptoms reported by
pesticide applicators are headache, rheum,
cough, skin rash and sneezing. Pesticide ap-
plicators reported four times higher symptoms
of ill health than other household members who
do not normally handle pesticides. Although,
households recognized pesticides as an im-
portant cause of ill health, some of the symp-
toms have been accepted as norm by individu-
als who apply pesticides. Official data on pesti-
cide poisoning in the country is most likely to
be seriously under-estimated as applicators
visited formal health centers for medical assis-
tance in only 2% of poisoning cases reported.
There is a high likelihood that households in the
study area under-estimated pesticide-related
health costs in making farm production deci-
sion-making. Approaches to use economic in-
struments for reliable monitoring and reporting
procedures to formulate appropriate policies
and regulations to minimize exposure to pesti-
cides are recommended. Health planners and
policy makers should aim at reducing the risks
posed by pesticide to farm households by, im-
proving awareness of farmers; promote com-
plementary approach (e.g. Integrated Pest
Management) and, use of economic instruments
and improved surveillance to bridge the gap in
the documentation of pesticide poisoning cases
among farmers.
Keywords: Occupational Health; Healt h Policy;
Pesticide Externality; Agriculture-Health Linkage;
Consumer Protection
Pesticides play an important role in minimizing po ten-
tial losses of agricultural production and livestock.
However, the chemicals have the characteristics to pro-
duce joint outputs because they usually generate the in-
tended outputs (saving crops from damage) and, simul-
taneously producing unintended outcome such as nega-
tive impacts on the environment and human health.
Globally, pesticide poisonings in the agricultural sector
accounts for between 250,000 to 370,000 human deaths
annually [1], most of these deaths occurred in develop-
ing countries. The cost of public health impact of pesti-
cide use in the USA is estimated at US$ 1.1 billion an-
nually [2], although figures for developing countries is
much lower [3]. While var ious efforts have been made to
minimize pesticide-related health problems including
changing from more toxic chemicals to less toxic ones
(e.g. from organochlorines and organophosphates pesti-
cides to pyrethroids), and warning labels to communi-
cate risk information to users [4,5], increases in the
quantity of pesticides and exposure to the chemicals
continue to fuel concerns about human health problems
associated with pesticides. Most of the environmental
impacts assessment on pesticides was conducted in de-
veloped countries and, only few empirical studies have
O. C. Ajayi et al. / Health 3 (2011) 631-637
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
assessed non-intended negative environmental effects of
pesticides in Africa. Documented cases of environmental
impacts in Africa focused on pesticide residues and the
contamination of water [6,7] and degradation of bio-
logical capital of ecosystems [8].
The effects of pesticides on human health in the de-
veloping regions have been eliciting much interest be-
cause most of the pesticide poisoning cases occur in that
part of the world. In Nicaragua, an extremely high risk
of acute pesticide poisoning estimated at 66,000 cases
annually, most of which occur particularly among agri-
cultural workers in rural areas has been reported [9]. In
Nepal, individuals who applied pesticides had signify-
cantly higher probability of falling sick from pesticide-
related symptoms than members of the same household
who were not exposed to chemicals [3]. Other empirical
field studies of the human health implications of pesti-
cides among agricultural workers and households have
been documented in the Philippines [10] and Ecuador
[11,12]. In Africa, field studies show that pesticides
cause changes in acetylcholinesterase inhibition and in-
creased health symptoms among agricultural workers in
Kenya [13]. The chemicals have been associated with
significantly impaired neurobehavioral performance am-
ong individuals who apply pesticides in the cotton fields
in Egypt [14]. Recent toxicological studies in South Af-
rica reported that exposure of children to pesticides and,
poisoning from the chemicals has emerged as an in-
creasingly important problem in the country [15]. Infor-
mation on human health implications of pesticides is
therefore essential to formulate appropriate policies for
reducing occupational risks from pesticide poisoning
among farm population [16].
The objectives of this study is to identify the human
health impacts of the use of pesticides on farm house-
holds in the cotton farming systems of Côte d'Ivoire us-
ing empirical field data and laboratory analyses. Spe-
cifically, the study answers the following questions:
“Are there human health problems associated with the
use of pesticides in agricultural households?” If yes,
“what are they?”; “How do farmers respond to the sym-
ptoms under actual level of attitudes and information on
pesticide-related human health symptoms?”
2.1. Description of Study Area and
Sampling Technique
The study was undertaken in northern Côte d’Ivoire
situated between latitude 8˚ and 9˚ North and Longitude
5˚ and 6˚ West. In addition to the regional capital town
of Korhogo, the major towns within the area of study are
Ferkéssédougou, Tafiré, Niakaramadougou and Katiola.
The area is predominantly populated by the native Sen-
oufos, although there are few pockets of other immi-
grants such as Peulhs, who are mainly livestock farmers
and Dioulas who are essentially traders. The agricultural
economy of the study area is dominated by cotton and
cereal production. Although the quantity of pesticides
use in African agriculture is lower than global figures,
cotton is one of the few crops where large quantities of
pesticides are used in the co ntinent. The use of pesticides
in Côte d’Ivoire is p articularly reinforced by historic and
several government policies that have promoted cotton
production and pesticide use. An example of such poli-
cies is the distribution of free pesticides to cotton farm-
ers on a standard dose for every hectare of cotton they
cultivated. The details o f these policies and oth er institu-
tional supports to promote cotton and pesticid e use in th e
study area have been documented [17,18] using an eco-
nomic framework developed by Waibel to analyze crop
protection policies and how such policies contribute to
promoting the use of pesticides in developing countries
[19]. Two sites were selected from the study area: Ka-
tiola is located in the southern part of the main cotton
producing zones and historically, pesticides have been
used for relatively shorter period (less than two decades)
in this site. Korhogo is located in the core cotton zone in
the northern part of the country and, intense use of pesti-
cides has taken place in the site for longer period span-
ning about four decades. Using stratified random sam-
pling technique, two villages were selected from Katio la
and three villages from Korhogo. A representative ran-
dom sample of 33 households was selected in each vil-
lage, i.e. a total sample size of 132 households. The de-
tails on the selection of households are documented
elsewhere [4].
2.2. Data Collection
Three sets of information that were identified to be
important for the objectives of the study were collected
using different approaches .
2.2.1. Field Monitoring of Pesticide Application
We collected information on the type of pesticides ap-
plied, quantity applied, duration of application (proxy
for exposure) and protective clothing worn by pesticide
applicators. Other data collected include the method of
transportation of chemicals from households to farms,
precautionary measures taken against wind, dosage and
method of mixing pesticides, type and condition of
equipment used. The information was obtained through
post-application interviews conducted by the trained
resident field technician and assistants immediately (the
same evening or the next day) that cotton farmers spray-
ed their fields. In some cases, the field research assis-
O. C. Ajayi et al. / Health 3 (2011) 631-637
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
tants followed farmers to the field and collected the
same information through direct observation. The data
collection process for this set of information was carried
out each time that farmers sprayed their fields.
2.2.2. Household Health Monitoring Survey
After each pesticide application, the specific person(s)
within the household who carried out pesticide applica-
tion in cotton fields (usually the male head of household)
was interviewed to collect information whether he ex-
perienced any acute health symptoms associated with
pesticide application. In this study, an acute health sym-
ptom that is reported by a pesticide applicator is associ-
ated with pesticide application only if the victim did not
suffer from the symptom before applying, but it began
only during or within 24 hours after applying pesticides.
Similar time limit has been used in other studies [20]. It
is possible that the time limit may underestimate health
costs since some symptoms take much longer to appear,
but our focus is on acute symptoms only. We wanted to
avoid the possibility of including other symptoms that
are not related to pesticides. Self-reporting of health
symptoms is an approach commonly used by researchers
to estimate risks of acute poisonings from agricultural
pesticides [3,9,20].
2.2.3. Residue Analysis
Pesticide residue analysis was carried out to investi-
gate a possible relationship between the health symp-
toms that were reported by applicators and, level of
chemical exposure. In one of the field application of
chemicals, we superimposed two pieces of new clothing
material (20 m × 20 m) each on pesticide applicators a
few minutes before they began spraying operation. The
pieces of cloth were collected at the end of spraying op-
eration, wrapped in aluminum foils and taken to the
laboratory for residue analysis. The pesticide deposits in
the tissue materials were extracted and analyzed in an
eco-toxicological laboratory located in Côte d’Ivoire.
The results of the extracted residues were reported in
micrograms (g) of active ingredient per cm2 of body
surface. It is expected that the quantity of insecticides
that would normally have fallen on applicators during
spraying are abso rbed by the cloth tissues.
3.1. Health Symptoms Associated with
Pesticide Application
Pesticide applicators reported health symptoms once
for every five times (20%) that they carried out spraying
operations. These were the symptoms that began during
or within 24 hours after spraying operation. Applicators
mentioned that “nothing happened” (‘rien à signaler’)
during the remaining 80% of the times that they carried
out pesticide application, i.e. they said they did not en-
counter extraordinary health problems that are beyond
normal. There is a wide difference in the behavior of
pesticide applicators across the two study sites. In Kor-
hogo site that has a longer history of pesticide use, ap-
plicators reported health symp toms and seek attention in
only 8% of the times that they apply pesticides. This
figure contrasts with 37% in Katiola site where pesti-
cides use began at a more recent period. In both regions,
the symptoms reported were those applicators perceived
to be the severe cases. The results compare with similar
study in Kenya where 10% of the individuals that are
exposed to pesticides experienced health symptoms dur-
ing spraying operations and, a quarter did so much later
after applying pesticides [13].
Several types of symptoms were mentioned by appli-
cators who reported one symptom or the other. The five
most economically important among these are headache,
rheum, cough, skin rash and sneezing, in decreasing or-
der of occurrence (Table 1).
These five symptoms alone accounted for 84% of all
the symptoms reported. In Katiola, a wider range and
higher number of symptoms were reported. These key
symptoms are cough (24%), headache (19%), Sneezing
(16%), Rheum (15%) and skin rash (9%). In contrast, there
were fewer number of symptoms reported in Korhogo as
three symptoms dominate. The three symptoms which to-
gether account for 85% of all the symptoms reported
Tab le 1 . Key health symptoms reported by pesticide applica-
Type of
Frequency of report of specific symptom relative to the
total number of symptoms reported (%)
(# of households = 127)1
Rhume 18
Cough 17
Skin rash13
symptoms 16
Total 100
Note: Figures are based on those who r eported health symptoms only; 1 Five
farmers in Katiola site did not have complete health information and were
dropped from the computation of this table.
O. C. Ajayi et al. / Health 3 (2011) 631-637
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in the site are headache (38%), skin rash (24%) and
rheum (23%). Pesticide applicators treated almost all
(98%) the reported symptoms using homegrown meth-
ods or through purchase of drugs across-the-counter
within or around the villages. Only in 2.2% of the cases
(1.5% in Korhogo site and 2.4% in Katiola site) did pes-
ticide applicators visit official health centers for medical
The results of the weekly household health monitoring
data provide additional insight into the occurrence of
health symptoms between pesticide applicator s and non-
applicators within the same household. Occurrence of all
types of symptoms (i.e., whether associated with pesti-
cides or not) that were reported by all household mem-
bers shows that pesticide applicators had four times
greater risk to fall sick (report an illness) than other
members of the household (non-applicators) with whom
they share similar socio-economic and livelihood condi-
tions. Pesticide applicators constituted 17% of the entire
household popu lation , but th e illn esses that th ey reported
accounted for 45% of all the illnesses (morbidity) re-
ported by members of the households. Similar studies in
cotton fields in Egypt revealed that after controlling for
age and education, field and laboratory tests show that
pesticide applicators (both adults and children) per-
formed significantly worse on the majority of neurobe-
havioral tests compared with the “controls” who are
those not working in agriculture [14]. In Nepal, the cost
of health care is reported to be eight times higher for
individuals who spray pesticides than others in the same
household who are not directly exposed to chemicals [3].
3.2. Laboratory Tests of Pesticide Exposure
among Pesticide Applicators
Given that the symptoms discussed above were based
on reporting by farmers, we analysed pesticide residues
on the clothing imposed on pesticide applicators to pro-
vide some insights into whether the health symptoms
mentioned above are indeed linked to pesticide exposure
or not. The quantity of pesticide residues that was ex-
tracted from the cloth tissue that was imposed on pesti-
cides applicators is presented (Table 2).
Based on the laboratory residue analysis, the total
quantity of active ingredients residues which fell on the
applicant’s body during the spraying season is estimated
at 202 g for every cm2 of the applicant’s body in Kor-
hogo site in contrast with 91 g in Katiola. This is
equivalent to 2.02 × 106 g per 100 cm2 i n Korhog o and
9.06 × 105 g per 100cm2 in Katiola site. The results im-
ply that pesticide applicators in cotton fields of Korhogo
site face two times higher risk of dir ect exposure to pes-
ticides than their counterparts in Katiola site. The dif-
ferences in exposure risk is explained by three related
Table 2. Estimated quantity of pesticide residues (g of active
ingredient) falling on applicators’ body throughout the pesti-
cide spraying season.
Description of residue measuredKorhogo
site (n = 35) Katiola
site (n = 34)Pr > T
Extracted residue per 1 × 1 cm area 202 91 0.1950
Quantity of pesticide residue per
100 × 100 cm area of cloth tissue
(extrapolated) 2.02 × 106 9.06 × 1050.1950
Quantity of pesticide residue per
150 × 150 cm area of cloth tissue
(extrapolated) 4.54 × 106 2.04 × 1060.1950
factors: larger size of cultivated cotton fields, use of
higher total quantity of insecticides per household,
longer duration of exposure to chemical spraying of the
bigger cotton fields. Given the inadequate use of protect-
tive clothing by pesticide applicators, the odds are that
the extracted residue s would be absorb ed into the sk in of
the applicators. The occurrence of p esticide drifts is high
in the study area because some farmers prefer to spray
their cotton fields when the wind speed is high [4]. The
reason is that they perceive that high wind speed helps to
spread the chemicals much more widely to a larger field
area and thus contribute to reduce the quantity (and cost)
of pesticides that they need ed to apply. The results above
showed that pesticide applicators in Korhogo are more
exposed to pesticides but the number of health symp-
toms that they reported is lower than in the Katiola site.
The possible exp lanations for these results are presented
in details in section 5.
4. Discussions
4.1. Cases of Pesticide-Related Health
Farmers in Korhogo site use higher quantities of pes-
ticides and are exposed to chemical spraying for longer
period (as they cultivated much bigger cotton fields than
their counterparts in Katiola. However, contrary to theo-
retical expectation, farmers in Korhogo reported a lower
number and range of health symptoms. Symptoms were
reported in 8% of the times that farmers in Korhogo ap-
plied pesticides in con trast with 37% in Katiola. In addi-
tion, for the health symptoms that were reported by
farmers, only in 2% (1.5% in Korhogo in contrast with
2.4% in Katiola) did farmers visit health centres to seek
medical assistance. The results also show that the longer
the period that farmers have been spraying pesticides,
the lower the proportion of the self reported health
symptoms that they present to health centres for medical
assistance. A number of reasons may explain the attitud e
O. C. Ajayi et al. / Health 3 (2011) 631-637
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of farmers regarding pesticide-related health symptoms
and visits to health centres to seek medical assistance.
The first possible reason is that over time, farmers have
been well trained and acquired sufficient skills to ha ndle
pesticides and to minimize exposure to the chemicals.
Second, due to the longer period in which farmers in
Korhogo have been spraying pesticides, they may have
developed home grown methods to treat the symptoms
on their own (especially the one that are not very severe)
and hence, did not visit formal health centres. Third, the
proportionately low visits to formal health centres may
be a reflection of the non availability of formal health
centres within easy reach of farmers, given the general
dearth of health facilities in most parts of the rural areas
of Côte d'Ivoire. Fourth, farmers have become accus-
tomed to the occurrence of human health hazards of pes-
ticides over a long time and have accepted them as part
of the necessary cost of doing farm business, rather than
regarding the problems as extra ordinary phenomenon.
As one of the farmers in Korhogo site puts it; ‘a child
who goes to fetch water in the stream should not expect
that his clothes will remain dry when he returns to the
village’. Fifth, the high cost of medical consultation is
unaffordable to many smallholder households and, they
were unprepared or unable to pay the high costs (relative
to home grown methods) associated with visits to formal
medical centres. Irrespective of the reasons for the low
proportion of cases for which formal medical assistance
was sought by pesticide applicato rs, these results sug g est
that the official records of pesticide-related symptoms
and pesticide poisoning are most likely under-estimated
in Côte d’Ivoire.
Studies from other parts of the world reported simi-
lar results showing that the proportion of those who seek
medical care is much lower than those who reported
acute symptoms from pesticide exposure indicating that
official data on pesticide poisoning is seriously under-
estimated [9,12,21,22]. This is so as only the health
symptom cases that are formally reported in health cen-
ters could be documented. Previous studies in other parts
of the world reported similar results where farmers vis-
ited health centres in only very small proportion of cases
of pesticide-related health symptoms. A study in Indon e-
sia, found that less than 1% of pesticid e applicators went
to a health center with symptoms related to pesticides
[20]. Based on various studies, estimates show that the
officially documented figures of pesticide poisoning in
South Africa are about 5% - 20% of the true rates [21].
At global level, official documentation of health poison-
ing cases is estimated at only 17% for developing coun-
tries [22]. Among cotton farmers in Zimbabwe, only a
very small proportion of the health symptoms associated
with pesticides were formally reported in health centres
either because farmers treated the symptoms as minor
problem that do not necessitate medical attention or th ey
rely on home grown treatments [23]. In general, the offi-
cial documentation of (unintentional) pesticide poison-
ing cases is linked to the level of eco nomic development
of the country, i.e. poorer countries tend to have lower
documentation ratios and vice versa. One of the prob-
lems posed by under-reporting of pesticide related health
problems is that it does not allow policy makers to fully
appreciate the extent of unintentional pesticide poisoning
and to formulate appropriate policy interventions.
4.2. Exposure to Pesticides and
Applicators’ Response to Health
The results of the laboratory residue analysis in this
study reveal that applicators in Korhogo site (where pes-
ticides have been used for a longer period of time) faced
greater level of exposure to pesticides than Katiola site,
but contrary to expectation, the willingness to invest on
pesticide-related health expenses is lower in Korhogo
site. The results do show that applicators in Korhogo site
were not more careful to avoid risks of exposure than
their counterparts in Katiola. Rather, there are indica-
tions that as the number of years of experience with pes-
ticide spraying increases, pesticide applicators tend to
think less of the pesticide-related health symptoms as
special problems and so it is not perceived as a ‘cost’ to
them. Over time, applicators perceive health symptoms
as ‘normal occupational hazards’ that should be expected
with applying pesticides. This raises the threshold of
pain, duration and severity that must be associated with a
symptom before it is perceived as “beyond normal” and
qualified for special mention an d requ iring special h ealth
care. A study in Asia reported that pesticide applicators
tend to accept a certain level of illness as part of the
work of farming [20]. In a similar study in Nepal, it was
reported that due to the perceived low cost of pesti-
cide-related health costs in comparison to farm produc-
tion costs, farmers do not take much cognizance of
health costs when making farm production decisions to
use or not use pesti c i des [3].
A number of efforts have been made to minimize pes-
ticide-related health problems including changing from
more toxic chemicals to less toxic ones (e.g. from or-
ganochlorines and organophosphates pesticides to pyre-
throids), and featuring pictograms on pesticide labels to
communicate risk information of the chemicals to users
[4,5]. While these efforts have helped in some cases,
increases in the quantity of pesticides and exposure to
the chemicals continue to fuel concerns about human
health problems associated with pesticides.
O. C. Ajayi et al. / Health 3 (2011) 631-637
Copyright © 2011 SciRes. Openly accessible at http://www.scirp.org/journal/HEALTH/
5. Conclusions and Policy Implication
We conclude that exposure to pesticides and occur-
rence of ill health symptoms is evident in agricultural
households in the cotton growing areas of Cote d’Ivoire.
If human health implications of pesticides are taken in
cognizance, the cost of using pesticides will increase.
Disregarding human health costs of pesticides in eco-
nomic and policy analysis will result in upward biased
estimates of the economic optimum of use of the chemi-
cals. Therefore, it is crucial to understand the linkage
between pesticides and the cost of human health arising
from their use especially in developing countries where
regulations are poorly implemented and farmers’ know-
ledge of safe handling procedures is inadequate. Al-
though precautionary measures against exposure to pes-
ticides are being promoted, occupational poisoning from
pesticides still occurs in rural households and it consti-
tutes a major concern in agricultural development plan-
Cotton farmers in Cote d’Ivoire recognize pesticides
as one of the important causes of ill health, but over the
years they have accepted some of the symptoms as a
norm and integral part of pesticide-spraying operation.
There is a high likelihood that households in the study
area under-estimated pesticide-related health costs in
making farm production decisions due to information
gap, and the wrong perception about the symptoms. The
level of awareness and knowledge of households should
be improved to reduce the risks posed from pesticide use
to agricultural households. A complementary approach is
to actively promote pest management options (e.g. Inte-
grated Pest Management) which minimize the quantity
of chemicals used and exposure to occupational hazards
among farm households.
There are gaps in documentation of pesticide poison-
ing as only a very low proportion of cases of health
symptoms mentioned by past applicators (2%) are re-
ported in formal health centres. A mechanism to facili-
tate formal documentation of pesticide poisoning cases
should be put in place. One approach to achieve this is to
use economic tool in pesticide policy-making process
offering incentives such as free medical assistance to all
victims of pesticide poisoning cases in health clinics.
Reliable monitoring, assessment and reporting proce-
dures are necessary to formulate appropriate policies and
regulations to minimize exposu re to pesticides.
The authors thank the University of Hannover Germany for the fi-
nancial assistance provided to the principal author during the field
study and, to the cotton farmers who collaborated with us in the study
for sharing their time with us. The field data collection and language
translation support provided by the study’s research assistants—Fofana
Aly, Benoït Kouadio, Bakayoko Tiehoulé, Fulbert Kouadio and Fozana
Diarassouba—are gratefully acknowledged.
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