A study of pesticide safety and health perceptions among pesticide applicators in Tarrant County, Texas.

Introduction

Although the value of pesticide use to control disease on crops, in homes, and on people is well documented (Health Canada, 1993; Holman, 2003; Subramanyam, 2002) and the pathology of exposure well studied (Abrams, Hogan, & Maibach, 1991; Furtaw, 2001; Guyatt, Gotink, Ochola, & Snow, 2002; Karalliedde, Edwards, & Marrs, 2003; Lisk, 1970; Mackness et al., 2003; Miller, 1975; Thrasher, Heuser, & Broughton, 2002; Walker & Nidiry, 2002; Waichman, Rombke, Ribeiro, & Nina, 2002), users' knowledge, attitudes, and beliefs about safe use of--or, conversely, exposure to--pesticides has not been well studied. The research has dealt with the effects of pesticides on human health. For the most part, this research has focused on commercial applicators who work in urban areas, as well as agricultural workers and ranchers from rural areas (Brender, Honchar, Alexander, & Beauchamp, 1988).

The present study assessed safety knowledge and health perceptions among licensed pesticide applicators in Tarrant County, Texas. The Texas Pesticide Regulations specify that an individual may not use a restricted-use or state-limited-use pesticide without a license obtained from the Texas Department of Agriculture (Texas Department of Agriculture, n.d.). The regulations also require licensed applicators to attend continuing-education classes to keep their licenses current. Included in this study were employees of parks departments, municipal golf courses, commercial pesticide companies, lawn care services, and other pest control organizations. Farmers and ranchers also were included since they too hold limited-use applicators' licenses.

In addition to determining the health beliefs and safety knowledge of such pesticide applicators, the purpose of this study was to determine if there was an association between their health beliefs and pesticide safety knowledge. This connection is important because the knowledge and beliefs of these workers can have either a positive or a negative impact on their own safety or that of their crews.

Methods

The survey questions addressed demographics, general pesticide usage, safety knowledge, and health concepts regarding pesticide risk perceptions and the respondents' confidence in their ability to perform safety tasks (Figure 1). This instrument, consisting of 32 questions, accessed general pesticide safety knowledge and the health beliefs of the applicators regarding pesticide safety. It was distributed at a continuing-education class sponsored by the Texas Agriculture Extension Service. To maintain a pesticide license, workers are required to acquire a specific number of continuing-education units (CEUs) per year depending on the type of licenses they hold. CEUs are earned by attending classes such as the one offered quarterly by the Texas Agriculture Extension Service. The survey was distributed at the attendee registration table, and completed surveys were voluntarily returned to the investigator. No precautions were taken to avoid multiple responses from any one person.

The self-efficacy and health belief portions of the survey were based on the Health Belief Model (HBM) of Strecher and Rosenstock (1997). The model assumes that people take action related to health behaviors because of fear of disease. Motivation to act appropriately is related to the degree of fear (perceived threat, susceptibility severity, or all three) as long as the potential benefits (perceived benefits) are valued. In 1988, Rosenstock added the concept of self-efficacy (confidence in one's ability to perform the action) to more accurately reflect lifestyle behavior changes such as smoking, overeating, or being sedentary. Although the HBM was originally developed to explain health behaviors, researchers have suggested that it could be used as a framework for developing change strategies (National Institutes of Health, 1995).

Categorical data were entered and analyzed with the Statistical Package for the Social Sciences (SPSS), version 10.0. Descriptive frequencies were identified, and correlation analysis was performed. To describe the relationships between knowledge, health belief, risk perceptions, and self-efficacy, or confidence in the ability to perform tasks, Spearman rank correlation coefficients were used with an alpha level of .05 (Strecher & Rosenstock, 1997). Spearman rank correlations were also used to determine if a correlation existed between age groups and number of years of work with pesticides and knowledge scores.

Results

A total of 89 individuals responded to the survey. In this cohort, 65 percent (n = 57) of the respondents were more than 40 years of age. The number of years applicators had worked with pesticides was fairly evenly divided. Thirty-three percent (n = 29) had worked one to four years, 25 percent (n = 22) five to 10 years, and 42 percent (n = 37) more than 10 years (>10 years of exposure). Ninety-two percent (n = 81) of the respondents reported their current health status as good or excellent. Seventy-four percent (n = 65) of the respondents stated they would use the same types of pesticides at home.

The yes-or-no question "Inhaling pesticides is the most common form of exposure" was answered correctly by 58 percent (n = 52) of the respondents, and "When transporting pesticides, you don't need to wear protective clothing" was answered correctly by 82 percent (n = 73) of the respondents. Table 1 shows that the distribution of answers to questions related to knowledge scores was significantly associated with the use of personal protective equipment (Spearman R = .267) and inversely related to health beliefs about direct exposure to pesticides (Spearman R = .255). There was no significant association between knowledge scores and scores related to risk perception, nor was there a significant association between knowledge scores and scores related to self-efficacy (Table 2).

Discussion

As mentioned earlier, at least 67 percent (n = 60) of the applicators indicated that they applied pesticides (were exposed to pesticides) in their work for five or more years. This circumstance might explain the high percentage of correct responses to knowledge questions concerning pesticide safety, and these results compared favorably with those of a similar study by Perry, Marbella, and Layde (2000). Out of the 15 knowledge questions, only two were not answered correctly by at least 90 percent (n = 80) of the respondents. It was surprising to find that the yes-or-no question "Inhaling pesticides is the most common form of exposure" (Table 1) was answered incorrectly by more than half (n = 52) of the respondents! Many respondents may have missed this question because of the attention given to protecting workers against pesticide inhalation. The question "When transporting pesticides, you don't need to wear protective clothing," however, was answered correctly by only 82 percent (n = 72) of the respondents. The most common form of applicator exposure is dermal exposure (Brender, 1988). Although the number of those who gave this response was significant, it was not as high as responses to other knowledge questions. This result may indicate a need for further training in this area.

The respondents reported that they believed dermal exposure was more likely to produce long-term adverse health effects than inhalational exposure. That belief was not expressed, however, with respect to immediate health effects after pesticide exposure. This result may indicate that acute exposure is not considered by the applicators to be as significant an issue as chronic exposure.

The sell-efficacy questions regarding ability to prevent exposure of oneself to pesticides were generally answered "confident." This result most likely indicates that the respondents know when to use protective equipment and have been taught how to use the equipment. The respondents appeared to be confident in their ability to protect themselves. On the other hand, respondents were found to be unsure about the perceived threats, susceptibility of severity (health risk) associated with pesticide use (exposure). This result may suggest that safety procedures are learned by rote rather than through an understanding of real health concerns.

Conclusions

Training of pesticide applicators has emphasized identification of the pest, use of the right pesticide, and safety in applying these economic poisons. Applicators' knowledge of pesticide application from a safety standpoint may be far different from their knowledge about the health effects of pesticides. One way to help erase the difference is to continue the educational process and to address specific items in a different manner. Further studies of beliefs and self-efficacy are needed to affirm this surprising finding. Expanding this study to cover participants in all pesticide classes taught by the extension service would give a better understanding of the finding. The content of these courses is designed to cover several aspects of pesticide use. Since there was some disparity between health beliefs and perceived risk, the continuing education course curriculum for pesticide safety should be designed to emphasize both short-term and long-term health effects from exposure to pesticides. Education of pesticide applicators, whether by initial or continuing education, needs to stress both acute and chronic adverse health effects of exposure to pesticides and both dermal and inhalation routes of absorption.

TABLE 1
Pesticide Safety Knowledge Questions (With Expected Answers)

Knowledge Question                               Number Who   Percent-
                                                  Answered      age
                                                 Correctly

The most important information source is             89         100
  the label. (Agree)
Chemical resistant coveralls are the only            88          99
  protection needed. (Disagree)
When transporting pesticides, you don't need         73          82
  protective clothing. (Disagree)
Inhaling pesticides is the most common form          50          58
  of exposure. (Disagree)
Wash your gloves and boots with detergent            83          95
  and water. (Agree)
Some pesticides have been shown to cause             89         100
  cancer in animals. (Agree)
Clothes worn while spraying pesticides can           86          97
  be washed with other clothing. (Disagree)
A dust mask is an effective substitute for a         87          98
  pesticide respirator. (Disagree)
Have a supply of water available when working        89         100
  with pesticides. (Agree)
There are no physical symptoms with pesticide        84          98
  poisoning. (Disagree)
Must wash immediately after pesticides touch         86          98
  skin. (Agree)
Eating or drinking is allowed while pesticides       89         100
  are being applied. (Disagree)
Any respirator will be effective for all types       85          99
  of pesticides. (Disagree)
Pesticides should not be sprayed near street         79          90
  drains. (Agree)
The pesticide concentrate is the chemical in         78          92
  its most toxic form. (Agree)

TABLE 2
Correlation of Knowledge Scores, Age Groups, and Number of Years
Working with Pesticides

Age        Health Belief           Self-Efficacy       Spearman R

31-40   I have been taught     N/A                        .421 *
        how to use personal
        protective equipment
        correctly.
31-40   N/A                    How confident are          .449 *
                               you that you are able
                               to get the proper
                               equipment from your
                               employer?

Years     Health Belief            Self-Efficacy            Spearman R
Working
with
Pesti-
cides

5-10      I'm too busy to use      N/A                        -.467 *
          personal protective
          equipment when using
          pesticides.
11-20     N/A                      If you were ready           .473 *
                                   to spray pesticides
                                   and the wind came
                                   up how confident are
                                   you that you would
                                   be able to wait until
                                   the wind died down to
                                   spray?
20+       Exposure to pesticides   N/A                         .518 *
          will not cause cancer.
20+       N/A                      If you were ready to        .518 *
                                   spray pesticides and
                                   the wind came up how
                                   confident are you that
                                   you would be able to
                                   wait until the wind
                                   died down to spray?

* Correlation is significant at the .05 level.

FIGURE 1
Questionnaire Completed by Respondents

Age                      () <21 () 21-30 () 31-40 () 41-50 () 51-60
How would you consider
  your health?           () Excellent () Good () Fair () Poor
How frequently do you
  apply pesticides?      () Seasonally () Periodically () Frequently
When you use them, do    () Month () Week () Day () 1/2 Day () >2 Hrs.
  you use them for a     () <2 Hrs.
Would you use them at
  your home?             () Yes () No

Do you agree or disagree with the following?

The most important information source is        () Agree   () Disagree
  the label.
Chemical resistant coveralls are the only       () Agree   () Disagree
  protection needed.
When transporting pesticides, you don't         () Agree   () Disagree
  need protective clothing.
Inhaling pesticides is the most common form     () Agree   () Disagree
  of form of exposure.
Wash your gloves and boots with detergent and   () Agree   () Disagree
  water.
Some pesticides have been shown to cause        () Agree   () Disagree
  cancer in animals.
Clothes worn while spraying pesticides can      () Agree   () Disagree
  be washed with other clothing.
A dust mask is an effective substitute for a    () Agree   () Disagree
  pesticide respirator.
Have a supply of water available when working   () Agree   () Disagree
  with pesticides.
There are no physical symptoms with pesticide   () Agree   () Disagree
  poisoning.
Must wash immediately after pesticides touch    () Agree   () Disagree
  skin.
Eating or drinking is allowed while             () Agree   () Disagree
  pesticides are being applied.
Any respirator will be effective for all        () Agree   () Disagree
  types of pesticides.
Pesticides should not be sprayed near street    () Agree   () Disagree
  drains.
The pesticide concentrate is the chemical in    () Agree   () Disagree
  its most toxic form.

Using the scale 1-5, please circle the number that most closely
matches your opinion.

                                     Strongly                Strongly
                                     Disagree                  Agree

I'm too busy to use personal
  protective equipment when              1       2   3   4       5
  using pesticides.
Direct exposure to pesticides
  is not harmful to human health.        1       2   3   4       5
A pesticide would not be put on
  the market if it weren't safe          1       2   3   4       5
  for humans to use.
Exposure to pesticides will not          1       2   3   4       5
  cause cancer.

                                       Very                    Very
                                     Unlikely                 Likely

Will getting pesticides on your          1       2   3   4       5
  skin cause an immediate health
  risk?
Will getting pesticides on your          1       2   3   4       5
  skin cause long-term harm?
How would you rate the health            1       2   3   4       5
  risk associated with pesticide
  use?

                                       Very                     Not
                                     Confident               Confident

How confident are you that you
  are able to prevent yourself           1       2   3   4       5
  from being exposed to
  pesticides?
If you were ready to spray pesti-
  cide and a wind came up how
  confident are you that you would       1       2   3   4       5
  be able to wait until the wind
  died down to spray?
If you needed advice on how to
  safely handle a given pesticide,       1       2   3   4       5
  how confident are you that you
  would be able to get advice?
How confident are you that you are
  able to get the proper equipment       1       2   3   4       5
  from your employer?
How confident are you that you are
  able to use the protective             1       2   3   4       5
  equipment correctly?

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Corresponding Author: Terrance B. Gratton, Assistant Professor, Department of Environmental and Occupational Health, Health Science Center, School of Public Health, University of North Texas, 3500 Camp Bowie Blvd., Fort Worth, TX 76107. E-mail: [e-mail].