Ann. occup. Hyg., Vol. 47, No. 1, pp. 61-70, 2003
© 2003 British Occupational Hygiene Society
Published by Oxford University Press
Determination of Potential Dermal and Inhalation Operator Exposure to Malathion in Greenhouses with the Whole Body Dosimetry Method
1 Laboratory of Pesticide Toxicology and 2 Laboratory of Efficacy Evaluation of Pesticides, Benaki Phytopathological Institute, Kifissia, GR-145 61 Athens; 3 Technological Education Institute of Crete, PO Box 140, GR-711 10 Heraklion, Crete, Greece; 4 Central Science Laboratory, Sand Hutton, York YO41 1LZ, UK
Received 16 July 2002; in final form 3 September 2002
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSION AND CONCLUSIONSREFERENCES |
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One of the steps during the authorization process of plant protection products (PPP) in the European Union is to evaluate the safety of the operator. For this purpose, information on the probable levels of operator exposure during the proposed uses of the PPP is required. These levels can be estimated by using existing mathematical models or from field study data. However, the existing models have several shortcomings, including the lack of data for operator exposure levels during spray applications by hand lance, especially in greenhouses. The present study monitored the potential dermal and inhalation operator exposure from hand-held lance applications of malathion on greenhouse tomatoes at low and high spraying pressures. The methodology for monitoring potential exposure was based on the whole body dosimetry method. Inhalation exposure was monitored using personal air pumps and XAD-2 sampling tubes. For the monitoring of hand exposure, cotton gloves were used in two trials and rubber gloves in another three. The total volumes of spray solution contaminating the body of the operator were 25.37 and 35.83 ml/h, corresponding to 0.05 and 0.07% of the applied spray solution, respectively, in the case of low pressure knapsack applications and from 160.76 to 283.45 ml/h, corresponding to 0.09–0.19% of the spray solution applied, in the case of hand lance applications with tractor-generated high pressure. Counts on gloves depended on the absorbance/repellency of the glove material. The potential inhalation exposures were estimated at 0.07 and 0.09 ml/h in the case of low pressure knapsack applications, based on a ventilation rate of 25 l/min. Both potential dermal operator exposure (excluding hands) and potential inhalation exposure were increased by a factor of ~7 when the application pressure was increased from 3 to 18 bar in greenhouse trials with a tractor-assisted hand lance, the rest of the application conditions being very similar.
Keywords: greenhouse; hand lance application; malathion; operator exposure
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSION AND CONCLUSIONSREFERENCES |
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According to the European Union Common Acceptance Directive 91/414/EEC (European Commission, 1991) a requirement for the authorization of plant protection products (PPPs) in the European Union is that the application of PPPs, following good plant protection practice, should have no harmful effects on human or animal health and no unacceptable influence on the environment.
Therefore, with respect to operator safety, two values are required: (i) the acceptable operator exposure level (AOEL) for each PPP; (ii) the operator exposure level (OEL) for each specific use of the PPP. If the AOEL is higher than the OEL, then that specific use of the PPP is considered to be acceptable. The AOEL value is determined from data generated in toxicological studies with the active substance of the PPP. These studies are carried out in accordance with officially accepted experimental protocols and evaluated in relation to the Uniform Principles of Directive 91/414/EEC. The derived AOEL value is a standard value, a characteristic of each active substance. However, the OELs are highly variable and can be influenced by a number of factors, including the agricultural practices followed, the climatic conditions and the training and aptitude of the applicator. In most cases the regulatory authorities estimate OELs through mathematical models. The most commonly used models are those from the UK (UK-POEM) (Pesticides Safety Directorate, 1992) and Germany (Lundehn et al., 1992). Another two models are the Dutch (Van Hemmen, 1993) and the North American (PHED) (PHED, 1992). There are significant differences in the fundamental assumptions used for the development of these models as well as in the type of data that have been used in the supporting databases (Kangas and Sihvonen, 1996).
The need for the development of a common European Predictive Operator Exposure Model has been recognized by the European Commission. Within the framework of a European Concerted Action a project (EUROPOEM) has been funded to collate European Union data in a common database in support of a European model (EUROPOEM, 1996). The model should include extreme PPP application conditions so that it becomes suitable for the whole of the European Union. These must range from the high temperatures in the greenhouses of the southern European zone to the cooler conditions in Nordic areas. In southern Europe the exposure levels of the operator are often considered higher than in countries such as the Netherlands or the UK. This may be due to the lack, in many cases, of modern automated application systems in the greenhouses and to the unsuitability of the available protective clothing for the southern European conditions.
For the development and validation of the EUROPOEM, additional operator exposure data, especially from the countries of southern Europe, have been considered as essential (Martinez Vidal et al., 1998). The required data should provide information on the degree of dermal and inhalation exposure of the operator, as well as the relationship between potential and systemic exposure. The dermal route is usually the main route of exposure during the handling of PPPs and it is considered to contribute the greatest proportion of the systemic exposure. Only when PPPs are applied as mists or fogs, as well as in the cases of volatile compounds, may inhalation exposure be more important than dermal exposure.
In the present study, the analytical method used for malathion determination was evaluated for possible matrix effects from the different sampling media. The levels of potential and actual dermal operator exposure and potential inhalation exposure were monitored following high volume applications of a 50% malathion emulsion concentrate formulation (50EC) on greenhouse tomatoes, at low (3 bar) and high (18 bar) spray application pressures. The efficiency of cotton coveralls for the protection of the operator was evaluated for the first two low pressure trials.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSION AND CONCLUSIONSREFERENCES |
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The potential dermal exposure to pesticide sprays can be measured with the patch method (Durham and Wolfe, 1962) or with the whole body dosimetry method (WHO, 1982; Chester, 1993). The patch method involves the use of a number of absorbent patches (gauze, cellulose paper, etc.) of a defined size attached to different parts of the body. After spray application the patches were analysed and the data from each patch were extrapolated to the defined surface area of the body where the patch was attached. This practice assumes that the spray solution deposition is uniform for each specific body area. This assumption can lead to wrong conclusions in many cases, usually resulting in a final overestimation of the exposure (Stamper et al., 1989; Machera et al., 1998). Although the patch method is simpler and less costly, the use of the whole body dosimetry method has been recommended (Machera et al., 1998) in order to overcome the above overestimates of the patch method. With this approach a purpose-made coverall, or any other protective garment normally worn by operators, can be used as the sampling medium.
Inhalation exposure measurements involve the use of a sampling device, mounted in the breathing zone of the operator and attached to a battery operated sampling air pump. There are limitations to this method, as the type of sampler used may have a significant effect on the efficiency of air sampling within the breathing zone. The efficiency of the sampler depends on a number of factors, including the size of the particles being sampled and the velocity of the air stream.
Field experiments
Application conditions. Two high volume applications of malathion 50EC were carried out on greenhouse tomatoes in the Marathon region near Athens. Foliar sprays were applied using a hydraulic knapsack sprayer at a 3 bar application pressure. The spray operator walked in and out of the rows of plants in the herringbone layout of the plant rows in the greenhouse, spraying all aspects of the vegetation isles. He moved the lance continuously up and down, from the bottom of the plants, with the spray nozzle facing upwards, to the top of the plants, with the nozzle spraying downwards, and back again. The dose rate of the malathion 50EC formulation was 8.9 l/ha of the product for the two trials and the volumes of spray solution applied were 5000 and 4873 l/ha, respectively.
On the same crop in Heraklion, Crete, three high volume applications were carried out using a hand lance at a pressure of 18 bar generated by a tractor-driven hydraulic pump. The tractor stood outside the greenhouse entrance while the spray operator held the spray lance (very similar to that of the Marathon knapsack sprayer) at the end of a high pressure hose connected to the tractor pump. The spray operator walked in and out of the herringbone pattern of plant rows and applied the spray in exactly the same way as in the Marathon trials. The dose rates of the malathion 50EC formulation were 6.4, 10.1 and 6.3 l/ha and the volumes of spray solution applied 3333, 4762 and 3448 l/ha, respectively, for the three trials. More details related to the application conditions in the two experimental sites are shown in Tables 1 and 2.
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Monitoring of dermal exposure
The potential and estimated dermal exposure of the operator during these applications was monitored by the whole body dosimetry method (WHO, 1982; Chester, 1993). In the two Marathon trials a 100% cotton coverall was used as outer protection. A Tyvek® coverall (Dupont), made of heat-compressed polyethylene fibre material, was worn under the cotton coverall. Absorbent cotton gloves were used over latex gloves to monitor the amount of spray solution impacting the hands. In the three trials in Heraklion only the cotton coverall was used. The operators in this case were provided with nitrile gloves, as in commercial practice. All the cotton garments had been pre-washed in a conventional washing machine without detergent. The Tyvek® coverall had been soaked in 10% acetone in order to remove any interference with the analysis.
Following the pesticide application, the coveralls and the gloves were allowed to dry in the shade. The cotton and Tyvek® coveralls were then cut in nine sections each, corresponding to different body areas (Fig. 1). The dry coverall sections as well as the gloves and the inhalation sampling tubes were packed individually in polythene bags and maintained under refrigeration until they were extracted for analysis. The amount of malathion reaching the outer coverall has been defined as potential dermal exposure and the amount detected on the inner coverall, which penetrated the actual PPE, as an estimate of the actual dermal exposure (Glass et al., 1999b).
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Monitoring of inhalation exposure
For the determination of the potential inhalation exposure a personal air sampling pump was used, operating at 2 l/min, equipped with an XAD-2 sampling tube (Chester, 1993). The XAD-2 tube was located in the breathing zone of the operator. Following application, the tubes were closed with two plastic caps at either end and transported to the laboratory for analysis.
Spray concentration
For the determination of the actual active ingredient concentration in the spray solution during the field applications (field spray tank, FST) and for the evaluation of concentration uniformity during spraying, samples of FST solution were taken at the beginning, in the middle and at the end of the application period. Each sample was analysed in triplicate.
Analysis
Chemicals
Malathion analytical standard 99.1% was obtained from Cheminova, malaoxon analytical standard 99.5% was obtained from Promochem and internal standard caffeine 99.5% from Chem Service. Stock solutions of malathion at concentrations of 100 and 1000 µg/ml were prepared in Pestiscan grade n-hexane. For the greenhouse studies the formulation malathion 50 EC (Vector Agro) was used. Pestiscan grade n-hexane was also used for the extraction of malathion from the media samples. Laboratory ‘spray tank’ solutions of malathion 50EC were prepared in HPLC grade water.
Equipment
Standard laboratory glassware and equipment, such as an overhead shaker and rotary evaporator, were used for the extraction procedure. A Hewlett-Packard 5890 Series II gas chromatograph, equipped with a septum-purged packed column inlet system, a nitrogen–phosphorus detector (NPD), an HP-1 fused silica capillary column (100% methylpolysiloxane, 5 m x 0.53 mm i.d. and 2.6 µm film thickness) and an HP 7673 autosampler were used for malathion determination. For instrument control and data analysis, HP 3365 Chem-station software was used.
Validation of the method and the analytical procedure
The method used for the quantitative and qualitative determination of malathion was validated. The analytical parameters determined were identification, linearity, possible matrix effects, calibration plots, limit of detection, limit of quantification and recovery.
Identification.
The malathion and caffeine peaks were confirmed in several temperature programmes and in columns of different polarity. At the same time the possibility of degradation product formation, such as malaoxon, was studied. The identification of the analytes was based on the retention time window (RTW), defined as the average retention time plus 3x the standard deviation for at least 10 measurements.
Linearity.
The linearity of detector response was studied at five different malathion concentration levels from 0.05 to 1.50 µg/ml with four injections at each concentration. The respective equation was established at the 95% confidence limit.
Study of matrix effect: calibration.
Possible matrix effects upon the analytical parameters from the different media types was studied. Blank samples of cotton coverall, Tyvek® coverall, glove and air sampling tubes were extracted in n-hexane. The calibration solutions were prepared with each hexane extract at three malathion concentration levels, i.e. 0.1, 0.5 and 1.0 µg/ml, together with a 1.0 µg/ml final concentration of caffeine as the internal standard. Five calibration plots were established, including the one in hexane only, with three measurements for each point. The different plots were compared by regression analysis and by one-factor ANOVA.
Limit of detection and quantification.
For the statistical calculation of the limit of detection (LOD) and the limit of quantification (LOQ) a calibration plot for malathion was established at concentration levels close to the expected LOD, i.e. at 0.01, 0.05 and 0.10 µg/ml. This plot was considered as suitable for malathion determination from all the different matrices. The LOD is defined as 3.3(Sy/x)/m and the LOQ as 10(Sy/x)/m, where Sy/x is the residual standard deviation and m is the slope of this calibration plot.
Recovery.
Pre-washed pieces of the different media were spiked with laboratory spray tank solution (LST). The LST was prepared from the commercial formulation in the same way as the field spray tank solution at a nominal active ingredient concentration of 1000 µg/ml. The analysis of the LST was performed as described under ‘Determination of malathion in the field spray tank solution’. The average concentration of the LSTs was found to be 904.6 µg/ml with a relative standard deviation (RSD) of 4.0%. The study of recovery was done by spiking pieces of cotton coveralls (30 x 30 cm) and gloves with three different volumes of LST, pieces of Tyvek® coveralls, also 30 x 30 cm, with two different volumes and air sampling tubes with one volume (three spiking replicates at each level). All the spiked pieces were extracted and analysed according to the procedure described under ‘Determination of malathion in coveralls and gloves’.
GC conditions
The injector and detector temperatures were set at 210 and 300°C, respectively. The oven temperature was set at 190°C isothermally. Helium was used as the carrier gas and as auxiliary gas for the NPD.
Determination of malathion in coveralls and gloves
The hexane volume for extraction of the coverall sections and gloves was 250 ml for coverall sections 1–3, 8 and 9, 350 ml for sections 4–6 and 7 and 150 ml per glove. Each cotton glove was analysed together with the respective latex glove. The extracts were analysed by GC–NPD with caffeine as internal standard at a final concentration of 0.5 µg/ml. The same procedure was followed with the nitrile gloves. The amounts of malathion determined were corrected for the respective recovery values in relation to the different matrices at the respective concentration levels.
Determination of malathion in the field and laboratory spray tank solutions
The FST and LST solutions were analysed to determine the actual malathion concentration. An aliquot of 1 ml of spray solution was transferred to a 100 ml volumetric flask, dried under a gentle stream of nitrogen and redissolved in 100 ml of n-hexane. The hexane solutions were analysed by GC–NPD with caffeine as internal standard at a final concentration of 0.5 µg/ml.
Determination of malathion in air sampling tubes: validation of the sampling method
The choice of XAD-2 for the air sampling of malathion was based on the work of Tuomainen and Kangas (1998). In addition, the XAD-2 tubes were validated for static recovery and retention efficiency as described by Capri et al. (1999). The static recovery indicates the ability of the sampling medium to retain the spike solution under storage. In this test the tube was fortified with 0.01 ml of the LST and stored at room temperature for 24 h. Three replicates from the fortified and the control samples were analysed.
The retention efficiency of the cartridges indicates the ability of the cartridges to retain the compound of interest when it is added in solution. The cartridges were fortified with the same volume of LST as before and connected to personal sampling pumps for 3 h in the dark at a flow rate of 2 l/min. Three replicates from fortified and control samples were analysed and compared to the cartridges from the static test.
For the determination of malathion in XAD-2 resin the glass tube of the cartridge was broken, both resin and glass pieces were put in a 50 ml tube with a Teflon screw cap and 30 ml of hexane was added and shaken in an overhead shaker for 30 min at 100 r.p.m. The hexane extracts were analysed by GC–NPD with caffeine as internal standard at a final concentration of 0.5 µg/ml.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSION AND CONCLUSIONSREFERENCES |
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Validation of the method and the analytical procedure
Identification
The RTWs for malathion and caffeine were 1.55–1.64 and 1.04–0.99 min, respectively.
Linearity
The detector response was linear for the malathion concentration range 0.05–1.5 µg/ml (r2 = 1.000, confidence limit = 95%).
Study of the matrix effect: calibration
The plots for malathion at concentrations of 0.1, 0.5 and 1.0 µg/ml in the matrix extracts from the gloves and the Tyvek® coverall are shown in Fig. 2. The lines for the three other three matrix extracts (filter, hexane and cotton) lay between the two lines shown in Fig. 2. The slope and the intercept values of the regression lines are within the confidence limits. This indicates that there were no significant matrix effects. The outcome was also confirmed with ANOVA and the respective P value was 0.999. The same conclusion was reached from the comparison of the RTWs for malathion and caffeine from the different matrices.
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Following these results it was concluded that the standard plot for malathion in hexane could be used for the quantitative determination of malathion from all the other matrices used.
Limit of detection and quantification
From the calibration plot established at 0.01, 0.05 and 0.10 µg/ml the LOD for malathion was estimated at 7.22 ng/ml (3.61 pg) and the LOQ at 21.9 ng/ml (10.9 pg).
Recovery
Malathion recovery from the media types at different concentrations was found to be in the range 48.8–68.1% for cotton coverall and 68.0–83.7 for Tyvek® and gloves. A higher recovery, 91.7%, was obtained for the XAD-2 tubes.
The relatively low recovery from the cotton coveralls was confirmed by repeatability studies. The repeatability determined was considered to be satisfactory, based on the RSD values, which varied from 5.4 to 8.6 for the whole procedure, and from the determined linearity of the calibration curve with R = 0.98.
Potential and estimated dermal exposure: potential inhalation exposure
The average malathion concentrations in the spray solutions for the two trials performed in Marathon were 889 and 905 µg/ml, respectively. In the three Heraklion trials they were 958, 1062 and 911 µg/ml, respectively.
The levels of dermal operator exposure following the low pressure application of malathion 50EC to greenhouse tomatoes in Marathon are presented in Table 3. The amount of spray solution reaching the upper part of the body was higher than the amount reaching the lower part in both trials. The total volumes of spray solution reaching the outer coverall was 25.37 and 35.83 ml/h, respectively, for these first two trials. These amounts correspond to 
0.05 and 0.07% of the applied volume of spray solution.
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The amount of spray solution that penetrated the cotton coverall and was absorbed in the Tyvek® is also shown in Table 3. The degrees of penetration through the outer coverall were 12.7 and 6.4% for the two Marathon trials. The permeability of the different parts of the coverall showed a high variation in both trials. The potential inhalation exposures of the operators were 0.067 and 0.086 ml/h based on a ventilation rate of 25 l/min.
The levels of dermal operator exposure following the high pressure applications of malathion 50EC on greenhouse tomatoes in Crete are presented in Table 4. The amounts of spray solution measured on the upper and the lower parts of the body were quite similar in each of the three trials. The total volumes of spray solution reaching the cotton coverall were 161, 229 and 283 ml/h, respectively, for the three trials. These amounts correspond to 0.09, 0.13 and 0.19% of the applied spray solution. The potential inhalation exposures of the operators were determined at 0.62, 0.56 and 0.34 ml/h, respectively, based on a ventilation rate of 25 l/min.
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The potential hand exposure measured on the gloves (cotton outer, latex inner) appeared very high in the two Marathon applications, reaching 74.27 and 115.02 ml/h, respectively. This was due to a leak in the handle of the hand lance as well as to an accidental spill in trial no. 2. It is also worth noticing that there were significant differences between the two hands in each case. In the first trial the operator, being left handed, had a much higher contamination on the left hand, whereas the reverse was the case for the second spray operator (Table 3). The values of spray liquid retained by the nitrile gloves in the three Heraklion trials were much lower at 4.53, 3.71 and 3.89 ml/h (Table 4).
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DISCUSSION AND CONCLUSIONS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODSRESULTSDISCUSSION AND CONCLUSIONSREFERENCES |
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The analytical methodology applied allowed for the qualitative and quantitative determination of malathion in the different sampling media, with a LOD of 7.22 ng/ml, a LOQ of 21.9 ng/ml and no matrix effects detected for the different matrices upon the analytical parameters.
The level of operator exposure is known to be very variable, depending on many different factors. In the two Marathon trials, at a low application pressure, the total potential dermal operator exposures to the spray solution were 25.37 and 35.83 ml/h, respectively. These potential dermal exposure levels are consistent with those determined in other trials under similar conditions, with dye tracers on greenhouse tomatoes (Glass et al., 1999a), where the respective values for the whole body dosimetry method were 39 ml/h on average.
The hand exposure values determined in the Marathon trials were much higher than the value of 6.0 ml/h determined by the same research team in dye tracer studies (Machera et al., 2001). However, the reasons for this, i.e. the leak in the sprayer lance and the accidental spill, seem to reflect common farm practices, where heavy handed contamination is often the case, due to general worker carelessness and the resulting poor maintenance of the application equipment. The glove contamination measured in the Heraklion trials, although much lower due to run-off of the spray liquid from the nitrile glove surface, is still considered very high. Overall, from these five trials it is concluded that hand exposure is a major part of the total potential dermal exposure of the operator. In the extreme case of the Marathon trials the potential exposure of hands accounted on average for 76% of the total potential dermal exposure.
In the trials performed at Heraklion, where a relatively high application pressure was used, the potential dermal operator exposure (excluding hands) was approximately seven times higher than the respective levels determined in the Marathon low pressure trials. However, this higher potential dermal exposure of the operator is expected when the application pressure is increased, due to the finer distribution of the spray solution and, consequently, the slower, non-directional deposition of the spray droplets. The tendency for increased potential dermal exposure under high application pressure was also observed in other greenhouse trials (Machera et al., 2001).
The potential inhalation exposure in the three Heraklion high pressure trials was higher than in the Marathon trials by a factor of approximately 7, similarly to the potential dermal operator exposure. These inhalation exposure levels were in a range similar to dye tracer high pressure applications in greenhouses (Machera et al., 2001).
The potential dermal contamination levels indicate that the AOEL values usually established for pesticides might be exceeded in many cases of commercial application practice, even if we consider a dermal absorption factor of only 10%. These findings highlight the need for the use of protective measures to be taken by the operator during the PPP applications.
The distribution of the spray solution on the protective coveralls is a parameter that varies dramatically depending on the characteristics of the treated crop and on the application method. Here the application pressure again seems to play a critical role. In the first two low pressure trials the greatest contamination was measured on the upper part of the body, due to the height of the treated crop (210–240 cm) and the necessary nozzle movement, 20–240 cm from the ground, to cover the lower surfaces of the bottom plant leaves and the tops of the plants, respectively. Secondary contamination of the operators was also observed from their close contact with the sprayed plants, as the plant rows were 90 cm apart, leaving only 30–40 cm free space between the plant isles.
In the three high pressure trials in Heraklion the distribution of contamination was much more uniform, with no significant differences between the upper and the lower parts of the body. This can be attributed to the size of the spray droplets and the resulting fairly uniform distribution on all surfaces. The height of the crop (and therefore the nozzle movement) in the case of high pressure sprays did not seem to be as important as in the case of low pressure trials due to a greater distance between plant rows (140 cm), which allowed the operators to avoid contact with sprayed plant surfaces. As is apparent from Table 1, the nozzle must be raised closer to the top of the plant rows when the pressure is low (3 bar). In the case of higher pressure this is obviously not needed (Table 2).
Another important factor for the protection of the operator is the permeability of the different parts of the coverall. From the values obtained, greater penetration was observed through parts of the coverall where the mobility of the operator created a greater amount of friction. This suggests that the coveralls used could be treated with water-proofing or water-repellent substances in those areas, so that they are less permeable only in those particular areas without any significant effect on the workers’ comfort when these garments are used in warm and humid working conditions.
The relatively low levels of the potential inhalation exposure determined in these high volume application studies indicate that although absorption through the breathing system is more intense than from the skin, this route of exposure may contribute to a lesser degree than the dermal route to the total systemic exposure, especially if recommended precautions, e.g. face masks, are used.
The increased application pressure in greenhouses results in a drastic increase in the potential dermal and inhalation exposure of the operators. Although farmers often use it with conventional hydraulic sprayers for effective coverage of dense plant foliage, it should be avoided, especially in greenhouses, as much as possible. The application pressure is a parameter that should always be taken into consideration for the estimation of operator exposure levels through mathematical models.
The light pure cotton coverall provided a protection factor of 0.90 in the Marathon trials, i.e. under the conditions and for the duration of these trials it prevented 90% of the spray solution coming into contact with the inner coverall. This level of protection is equivalent to the value of 0.9 produced in this case by the German model. The exact level of protection offered by gloves made of nitrile, or other materials of similar properties, is difficult to determine. In any case, if recommended gloves are used and they are put on and taken off the hands appropriately during use and they are also cleaned well after use, the protection factor against the spray solution could be practically 1.0, depending upon the duration of the spray applications and the properties of the materials involved. However, when gloves are removed or replaced incorrectly, cross-contamination often occurs, contributing to hand exposure and ultimately to the absorbed dose of the PPP.
Acknowledgements—The authors wish to acknowledge the financial support of the European Commission DGXII for this work, project number STM4-CT96-2048, and the technical assistance of Mrs P. Anastassiadou in the laboratory and the participation of Miss E. Goumenaki in the field work in Crete.
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FOOTNOTES |
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* Author to whom correspondence should be addressed.
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REFERENCES |
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A. ARAGON, L. E. BLANCO, A. FUNEZ, C. RUEPERT, C. LIDEN, G. NISE, and C. WESSELING Assessment of Dermal Pesticide Exposure with Fluorescent Tracer: A Modification of a Visual Scoring System for Developing Countries Ann. Hyg., January 1, 2006; 50(1): 75 - 83. [Abstract] [Full Text] [PDF]
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B. V. RAWSON, J. COCKER, P. G. EVANS, J. P. WHEELER, and P. M. AKRILL Internal Contamination of Gloves: Routes and Consequences Ann. Hyg., August 1, 2005; 49(6): 535 - 541. [Abstract] [Full Text] [PDF]
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