Introduction

Globally, there has been an increase in the inquiry on the knowledge of the dangers of chemicals in food which has aroused consumer concerns about food safety [1, 2]. This follows from consumer reports on the health effects of pesticides from their inappropriate use, exposing consumers to high amounts of pesticide residues in harvested foods [3–5]. Pesticide residues in food are directly related to the irrational application of pesticides on growing crops and a lesser extent, from residues remaining in the soil. Accumulated pesticide residues in food products that are absorbed in the human body are associated with human health hazards ranging from acute illnesses like; skin rashes, nausea, headaches, eye irritation, and shortness of breath to chronic toxic effects like; asthma, cancers, diabetes among other chronic illnesses [4, 6–8].

For numerous decades, pesticide use has intensified globally in agriculture, homes, and industries aiming at increasing productivity and reducing losses [4, 9–12]. In Sub-Saharan Africa, with a tropical climate that favors the growth and rapid multiplication of pests, pesticides are usually used at all levels of agricultural production, including on farms, to shield plants from pest attack and damage, to control weeds and parasites in livestock as well as in post-harvest control measures. It is now nearly impossible to produce food in tropical regions without using agrochemicals. However, considerations have been made in the climate change mitigation strategies rolling on the adoption of agroecology mechanisms [13, 14].

In developing countries, almost all fruits and vegetables grown commercially are sprayed with pesticides to combat pests and diseases. For example, a study done in 2014 at the two largest horticultural produce markets in Africa showed that 91% of the fruit and vegetable samples collected between 2012 and 2014 had pesticide residues, although these were compliant with the Maximum Residue Limits (MRLs) [15]. A comparative study done in Uganda among two groups of farmers (organic vs conventional farmers) still attests to the fact that food consumers are still exposed to the pesticide through the consumption of contaminated foods and drinks apart from direct exposures during spraying [16].

In most low-income countries like Uganda, pesticide regulation enforcement and support of the agricultural extension staff to guide farmers on pesticide application standards and dosage is very minimal if not done by implementing partners like Non-Government Organizations. Unlike export products, fresh produce sold at local markets is not analyzed for agricultural chemical residues. This raises concerns about the perceived safety levels of local food supplies compared to exported products [15]. For instance, a study in Uganda showed that 24.5% of farmers were not aware of any health risks of spraying tomatoes close to harvest time, almost 50% of farmers (45.8%) sprayed their tomatoes less than a week to harvest time, 29.2% sprayed their tomatoes on harvesting, with intentions to extend the shelf-life while 50% did so to attract consumers [17–19].

Another study in 2015 shows how farmers sprayed tomatoes 6 times the manufacturer recommended dosage and harvested these tomatoes 2–3 days after the last spraying session compared to the recommended pre-harvest interval of 4–7 days [18]. These phytosanitary practices increase pesticide residues in tomatoes. This is further exacerbated by the lack of a pesticide residue monitoring plan for conventionally grown food and specific surveillance for pesticide poisoning by the health sector [20].

Although developed countries use 75% of global pesticides; these apply them with strict regulations compared to developing countries which lack regulation enforcement. Although developing countries use the least quantities of pesticides, they use the most toxic ones [21, 22] resulting in increased risks of acute poisoning. The inappropriate use of pesticides in developing countries increases pesticide exposure and health risks to consumers. Approximately 25% of developing countries lack regulations and 50% of the WHO-region countries lack sufficient resources to enforce their pesticide-related regulations [23, 24]. Also, under existing international laws, highly toxic, banned, or unregulated pesticides are always exported to developing countries [25–28], posing health risks to consumers.

Although Uganda is transitioning to establishing a pesticide residue monitoring program, this has moved slowly and made the protection of public health unrealized. There is limited published work in Uganda about consumer risk perception toward pesticide residues in food. This study, therefore, in its novelty, contributes to new knowledge in the areas of risk perception among Ugandan consumers by unveiling the understanding of consumers’ risk perception towards pesticide-stained tomatoes, and their attitudes towards pesticide-stained tomatoes to justify the need for a National Pesticide residue monitoring program in Uganda.

Research questions

1. What is the risk perception of consumers regarding tomatoes stained with pesticides?
2. What are consumers’ attitudes towards tomatoes stained with pesticides?

Fig 1 illustrates the conceptual framework used in this study.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 1. Conceptual framework.

https://doi.org/10.1371/journal.pone.0247740.g001

Methods

Results

Demographic characteristics of consumers

The study registered all consumer responses, equally sampled by residence (rural, urban, and peri-urban). From the three sub-counties in each of the four districts of Uganda; (Northern region: Nebbi district, Eastern Region: Bugiri District, Central Region: Sembabule district, and Western region: Masindi district).

As indicated in Table 1 below, slightly more than half, 54.1% (253/468), of respondents were females, a majority, ≈51.0% (238/468) practiced farming as an occupation (refer to S1 File for other demographic characteristics), a majority, 84.4% (395/468) had attained a lower level of education. The mean age of participants was 37.7 years (SD±13.1, ranging from 18–88), with a majority of 54.7% (256/468) belonging to the age group below the mean age. From the qualitative results, interviews involved categories of tomato farmers 33.3% (12/36), tomato retail vendors 33.3% (12/36), and tomato wholesalers 33.3% (12/36) sampled in equal proportions in the 4 districts. i.e., three persons, per category, per district.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 1. Demographic characteristics of consumers.

https://doi.org/10.1371/journal.pone.0247740.t001

Consumer risk perception towards pesticide-stained tomatoes

Consumer risk perception was measured using a model with questions as provided in Fig 2.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 2. The model for assessing consumer risk perception towards pesticide-stained tomatoes.

(Perceived severity component).

https://doi.org/10.1371/journal.pone.0247740.g002

Consumer risk perception

Among consumers who were aware and knowledgeable about sold tomatoes containing pesticide residues, ≈95.0% (376/396) of them bought these pesticide-stained tomatoes (i.e., had a low-risk perception) compared to only 5.0% (20/396) who perceived tomatoes to be of high-risk to their health and withdrew from buying them (i.e., had a high-risk perception) as provided in Fig 3.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 3. Level of consumer risk perception towards pesticide-stained tomatoes.

https://doi.org/10.1371/journal.pone.0247740.g003

Factors associated with consumer risk perception and buying of stained tomatoes

From the Fisher-exact tests, consumer risk perception was not associated (p>0.05) with the demographics such as level of education P (0.975), Residence P (0.462), gender P (0.581), age group P (0.680), and marital status P (0.581), as indicated in the S3 File. However, further simple logistic regression analysis revealed that consumer risk perception was significantly associated with consumer awareness about residues in the sold tomatoes; where the proportion of consumers who were aware of tomatoes containing pesticide residues was 42.8 times more of a high-risk perception compared to the proportion of those who were not aware of the tomatoes containing pesticide residues. (Refer to results in the S4 File).

In Table 2, the consumer awareness about Pesticide residues was not associated with age- group, and level of education but significantly associated with gender, where male consumers were 1.77 times more likely to be aware of the pesticide residues in the tomatoes compared to their counterparts; and consumers who had never obtained pesticide safety information being 61% less likely to be aware of the pesticide residues compared to consumers who had obtained information on pesticide safety, OR 0.39 (95% CI: 0.24–0.64)

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 2. Logistic regression for consumer awareness about pesticide residues on tomatoes and some consumer demographics (crude Odds ratio).

https://doi.org/10.1371/journal.pone.0247740.t002

Consumer awareness about the pesticide-stained tomatoes was not associated with consumer level of education P (>0.05) but significantly associated with consumer risk perception P(<0.05) and the practice of buying stained tomatoes P (<0.05) as indicated in Table 3 below.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 3. Shows the fisher-exact tests for awareness about pesticide residues in tomatoes versus the consumer level of education and practice of buying stained tomatoes.

https://doi.org/10.1371/journal.pone.0247740.t003

General consumer attitudes towards pesticide-stained tomatoes

Pessimism towards pesticide-stained tomatoes.

Based on the percentages of pessimism, measured on a 3-Likert scale, a majority, 74.3% (347/467) of the consumers were pessimistic about the stains on the tomatoes compared to 2.4% (11/467) who were not sure, and 23.5% (109.6/467) who felt optimistic about the stains on the tomatoes in terms of worrisome, discomfort, and suspicion caused by the residues. (Details provided in S2 File and Fig 4).

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 4. Average negative perceptions/pessimism of consumers on pesticide-stained tomatoes in percentage.

https://doi.org/10.1371/journal.pone.0247740.g004

Optimism towards pesticide-stained tomatoes.

Based on the percentages of optimism, measured on a 3-Likert scale, Consumers’ positive attitude towards pesticide-stained tomatoes was low. On average, only 33.2% (155.3/468) of the consumers agreed with the statement that tomatoes sold on the Ugandan market are safe, compared to a majority of 61.1% (285.6/468) who disagreed with the statement while 5.7% (26.7/468) were not sure as provided in Fig 5 and indicated S2 File.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Fig 5. The optimism of consumers on pesticide-stained tomatoes.

https://doi.org/10.1371/journal.pone.0247740.g005

Consumer-level of trust in pesticide-stained tomatoes.

In terms of trust, based on the 3-scale, 77.7% (362/466) of consumers lacked trust and disagreed that tomato vendors have the characteristics of trust such as the competence to control the safety of tomatoes, the knowledge to guarantee tomato safety, honesty about the safety of the tomatoes, being sufficiently open about tomato safety and giving special attention to control the safety of tomatoes compared to 8.1% (37.6/466) who were not sure and 14.1% (65.4/466) who trusted tomato vendors (details provided in the S2 File).

Qualitative findings

Table 4 summarizes the qualitative findings of this study.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 4. Shows a summary of qualitative findings: This table includes perceptions on pesticide stained tomatoes from key informants and focus group discussants.

https://doi.org/10.1371/journal.pone.0247740.t004

Discussion

Very little information is available about the pesticide residue in tomatoes in Uganda and, consequently the risk of exposure to this. Therefore, the focus of this study was to determine the consumer risk perception towards pesticide-stained tomatoes and the attitudes (pessimism, optimism, and trust) toward pesticide-stained tomatoes. It employed a cross-sectional study design with a total of 468 consumers as respondents equally systematically sampled by residence and interviewed from each of the four districts (Northern Region: Nebbi District, Eastern Region: Bugiri District, Central Region: Sembabule District, and Western Region: Masindi District), thus a good representation of Ugandan consumers.

Characteristics of the respondents show that slightly more than half of the respondents were females as expected since data collection was done at the home level and the majority of the females stay home to take care [31] of home chores and are more involved in food buying and preparations, similar to findings by [32, 33] where 58% of women were involved in the purchase of meat and [34] where 73% of the female formed part of the study participants, more than three quarters were married women as interviews were conducted at homesteads and consent sought from adults making it more likely for the married women to be interviewed. This calls for public health and risk communication interventions to focus on and prioritize females when communicating the risks of pesticide exposure in food since they are more engaged in food preparations at home levels. Half of the respondents were farmers, given that Uganda has nearly three-quarters of its population engaged in farming, and this study was carried out in a rural setting involving vendors, buyers, and tomato growers. A majority had completed a lower level of Education, and a majority belonged to the age group <30 years as the Ugandan population is composed of 75% youths as the majority, 80% of these residing in rural areas [35]. From these characteristics, we can report that the consumers interviewed in this study were a good representation of tomato consumers in Uganda. Respondents of this study represent adult female consumers experienced with tomato farming and with adequate education attainment (majority with Ordinary level of education) to express risk perception towards pesticide-stained tomatoes.

Consumer risk perception ranked low, with a majority of consumers (95%) buying tomatoes that are well known to be stained with pesticide residues, a majority giving reasons that they have no alternative. Results from this study highly deviate from similar studies conducted in developed countries, such as Californian consumers, where 80% were safety cautious and checked the food items to see if they were opened or damaged [36], in Georgia, 89% considered testing of pesticide residues in food to be very important or somewhat necessary [31], and in Boston, consumers had a high-risk perception of conventionally grown produce compared to public health hazards [33], most of these were mainly triggered by the health effects of the contaminants such as pesticide residues and biological contaminants like disease-causing germs in the sold produce. More so, another study by [34] conducted in Athens Greece, shows how consumer willingness to pay for organically grown food was strongly linked to quality and security. Quality entails the aspects of food being free from any contaminations introduced in the process of its growth and the security aspect entailing a low risk to harm.

From the Turkish perspective, consumers’ willingness to pay for reduced pesticide residues in tomatoes was mainly determined by their risk perception about the residues, which is explained by the label on the purchased apples [37]. In this case, due to the different situations, in Uganda, unfortunately, tomatoes are not labeled with the residual contents and benefits of low pesticide residual levels. This could be the reason why most of the consumers in this study bought tomatoes. The vegetables on the market lack such information which could have triggered consumers to make their choices. This is a gap to be closed by authorities in charge of food safety and consumer protection to ensure that food is labeled in terms of chemical residues but also state if it is organically grown to protect the public from pesticide residual exposures. Uganda is lacking a stand-alone and comprehensive food safety policy that puts public health at stake for pesticide exposure. The existing Food and Drug Act is a bit outdated and merely captures specific food contaminants such as pesticide residues.

Results from this study are a piece of vivid evidence to be used as part of the advocacy statements in finding ways of establishing a stand-alone National Food Safety Policy and formulation of interventions for risk communication regarding food risks like pesticide residues.

A study on consumers’ willingness to pay for pesticide-free vegetables indicated how consumer awareness about the residues in vegetables and the residual effects on human health greatly influenced their willingness to pay for these vegetables. Consumers in this study were willing to pay 50% more for pesticide-free vegetables [38]. In the Ugandan context, the consumer’s low-risk perception of pesticide-stained tomatoes indicates a risk of increasing pesticide residue exposure if there lacks an alternative. As reported in other findings [19], our qualitative results from vendors and tomato farmers from the FGDs, indicate that the highly stained tomatoes are due to poor hybrid tomato seeds that need frequent spraying and vendors’ demand to spray these tomatoes before selling. Nevertheless, a low level of literacy to understand the pesticide label information and wrong perception that Mancozeb pesticide can harden the outer skin and increase tomato shelf life. From this misconception, tomato vendors only buy stained tomatoes presuming that these will stay for long on the shelf, are healthy & free from microbial contaminants.

Unlike other studies [31] from Georgia where consumers prioritize microbial contamination followed by pesticide residues as the first consideration before choosing to buy vegetables, tomato consumers in Uganda partly have a feeling that pesticide-stained tomatoes are free from pathogens and healthy, thus ignoring the pesticide stains on them. As reported, some think that pesticides are selective and only meant to kill plant pests and cure plant diseases. However, our logistic regression analysis indicates how consumer awareness about pesticide residues increases the chances of a high-risk perception, protecting consumers from residue exposure, although this is just for a few individuals, this is backed up by the risk perception consumer behavior theory under perceived severity of the risk associated with the choices under the conventionally grown foods. More interventions on tomato preservation techniques need to be disseminated by district agricultural extension departments targeting more tomato sellers who demand pesticide-stained tomatoes.

From our focus group discussion; all farmers claimed that vendors would only buy tomatoes with pesticide stains as these are thought to be healthy and would stay for long on the shelf before being sold to the consumers. On the other hand, vendors attest that stained tomatoes are healthy, look good, take long to go stale, and have a high resale value on the market.

From these findings, the Ministry of Agriculture Animal Industry and Fisheries needs to sensitize farmers and improve coordination and regulations on the sale and use of agro-inputs. Agro-input dealers, the immediate information providers to the farmers, need to be trained in Pesticide safe-use training. A recent unpublished survey done by UNACOH in 2020 reports that only 6% of the agro-input dealers in 12 districts had obtained the safe-use training which is required to be undertaken by all agro-input distributors and it is a prerequisite by law before an agro-input shop business is opened [39].

Tomato residues are given less attention by consumers probably because consumers lack knowledge of the dangers that the residues may impact on their health which in most cases takes time. From a model by Huang Chung [40] estimating the relationship between consumer perceptions, attitudes, and behavioral intentions (refer to the model in S7 File), choices (behavioral intentions) on buying food are influenced by perceptions and attitudes, which influence each other in addition to knowledge (information) from personal experience, evaluative criteria, and social demographics. All are based on consumer awareness about the pesticide’s potential ill effects and the social economic status of the consumer. Consumers of higher social-economic status are most likely to have a high educational level and consequently easily access all the necessary information about the effects of pesticide residues. These will tend to have a high-risk perception about the pesticide-stained tomatoes and are not likely to buy those stained with pesticides. However, this was not so with our findings. Consumer risk perception was not directly associated with the level of education and social economic status, but associated with awareness about pesticide residues. Consumers who were aware of pesticide residues were 42.8 times more likely to be of high-risk perception than those who were not aware. From our results, the low proportions (5%) of high-risk perception consumers may be attributed mainly to our sample containing low percentages of highly educated consumers (upper-level education, Table 1). This study is in line with a study by [34], who discovered that consumer willingness to pay for organic produce was not associated with social demographic characteristics. However, similarly, consumer willingness to pay dwelt much on the quality and safety of the food. Where consumers look for quality food free from contaminants and this is affected by their knowledge or awareness about the contaminants.

On the other hand, pesticide residue knowledge among the general public in Uganda is a new topic, and studies conducted along these lines are few, most of the time not intended to create awareness among the public on the potential ill effects of residues in food. From other related findings in this study, consumers have no access to sources of information on pesticide residues in food, with most of the information on pesticide residues acquired through radio and television media, followed by health professionals, depicting a significant gap in information accessibility and availability. Based on the results of the misconception that pesticide residues increase tomatoes’ shelf life, new studies on the origin of this misconception need to be conducted to challenge the practices of overdosing, which pose risks to public health.

Although this study had measures in place to ensure the accuracy of reported data, limitations were encountered due to recall bias. Respondents were asked to remember their food choices from the past month or weeks, which may not always be completely reliable. Some respondents may also feel sensitive when answering questions about consuming food contaminated with pesticides due to awareness of the potential dangers, leading to report bias. Therefore, this research has some limitations.

Conclusion

Although consumers in Uganda had a negative attitude towards pesticide residues on the tomatoes, their risk perception towards these pesticide-stained tomatoes ranked low, with a majority of consumers buying pesticide-stained tomatoes regardless of their level of education, age, and gender. This was all linked to a market lack of alternative organic tomatoes. However, awareness about tomatoes containing pesticide residues was associated with containing pesticide residues was 42.8 times more of a high-risk perception than consumers who were not aware.

There is a need by the government, through its line of Ministry of Agriculture Animal Industry and Fisheries (MAAIF), health information and risk communication entities, and Civil Society Organizations among other partners to sensitize the Ugandan population on the effects of pesticide residues. There is also a need to sensitize farmers on the right pesticide dosage, and compliance to the pre-harvest intervals as well as train agro-input dealers on the same relevant pesticide safety and handling modules since it is from these, that the farmers buy pesticides.

MAAIF should also hasten the establishment of the National Pesticide Residue Monitoring Program to protect Public Health from this chronic exposure to pesticide residues in agricultural produce.

Supporting information

Acknowledgments

The author would like to acknowledge the support from Diálogos participants and all efforts rendered by the Pesticides Use, Health and Environment (PHE) Project team, and the respective District Framers’ Association (DFAs) with which the study was conducted. DFAs supported highly in questionnaire translation into the respective local languages and in the data collection exercise.