**3. Results and discussion**

Based on the data obtained in the present study, it was observed that the case group had similar demographic characteristics to the control group but the last one without any pesti‐ cide exposure.

#### **3.1. Description of the population based on the surveys and clinical history**

*Group 1*. Field workers. 94 personal surveys were made from which 68% provided data re‐ lated to medical history. Only 71% of the participants provided blood samples, 69% urine samples and 46% seminal fluid samples. A small number of medical histories and samples were obtained since the participants had the liberty to leave the study at any time.

In the case group, a total of 77 men participated; the majority maintained contact with orga‐ nophosphate pesticides; the average age of this group was 40 years and 11 years of residen‐ cy in the site of the study with a maximum of 45 years. The average work years with pesticide exposure was 28, with a maximum of 50 years working in agriculture. Based on data from work history a 62% of the cases had contact with pesticides; from this percentage 43% applied them, 27% works in the places where they were applied and 30% works where they are applied. Only 18% of the field workers uses protection while applying pesticides (like gloves, special clothing for welding fumes, paint fumes o foundry fumes). These results suggest that field workers are chronically exposed to pesticides due to few safety precau‐ tions are taken to handle them. There for, it is of importance that the field workers receive training to be aware of the possible health issues related to pesticides exposure.

1 µL. Nitrogen (purity 99.999 %) was used as the carrier gas at a flow of 1.5 mL/min. The injector temperature was 180°C and the detector temperature was 300°C. The temperature program was as follows: initial temperature 220°C, increasing temperature at 9°C min-1 until the final temperature of 300°C was reached. Data was analyzed using a program Star Chro‐

The design of the study 1 was of the type "Case/Control", where 77 men integrated case group and 17 the control group. Participants of both groups were the same ages (18 to 70 years old). Control group did not have evidence of pesticides exposure. The sample size for the cases group represented approximately 5% of the total male population's in the range of

The study 2 was integrated by 39 nursing mothers between 17 and 39 years old, selected randomly among those that accepted to participate. All the other characteristics were similar

The nominal data were analyzed by group (in study 1) using contingency tables and Chisquare statistics. Continuous numeric data (age, height, weight, etc.) were reported with de‐ scriptive statistics (minimum, maximum, mean, median, and standard deviation). In study 1 there were analysis of variance comparing groups (cases *vs* controls) for the numeric and nominal variables. Several exposure indicators (reported by the literature, erythrocytes, VCM, and RDW) were analyzed by linear regression versus time of exposure, and pesticide amount on a particular body fluid. Also, multiple correlation coefficients were estimated be‐

For the study 2 beside of the descriptive statistics, some relationships were evaluated such as the use of protective gear, age, number of years of exposure, children's number, among others. The pesticide residues in breast milk were compared with the maximum residual

Based on the data obtained in the present study, it was observed that the case group had similar demographic characteristics to the control group but the last one without any pesti‐

*Group 1*. Field workers. 94 personal surveys were made from which 68% provided data re‐ lated to medical history. Only 71% of the participants provided blood samples, 69% urine samples and 46% seminal fluid samples. A small number of medical histories and samples

**3.1. Description of the population based on the surveys and clinical history**

were obtained since the participants had the liberty to leave the study at any time.

matography Workstation 5.51.

ages selected in the study.

tween several biological indicators.

**3. Results and discussion**

cide exposure.

limits stated by international organizations.

to study 1.

**2.7. Design and analysis of the studies**

316 Insecticides - Development of Safer and More Effective Technologies

In the case group besides being in contact with pesticides during work activities they are al‐ so in their place of residency; considering this background, the time of exposure is 16 years in average and 65% of them apply insecticides in their homes; 27% are applied with an an‐ nual frequency, 23% are applied semiannually, while 10% every 3 months and 8% monthly.

Some factors can exacerbate the toxicological effects caused by pesticide exposure, such as the consumption of alcohol and drugs. The present study found that 69% of the individuals of the case group consume alcohol with a monthly frequency, 16% consume less than 5 cigarettes dai‐ ly, 8% and 6% less than 20 cigarettes and the rest only 1 cigarette, 4% consumes cocaine, none of the cases consumes marihuana, nor intravenous drugs. Erection and ejaculation problems (4%) were found in case group. Case and control groups had problems having children (6%). Unlike the control group, the case group presented sexual transmission diseases; around 4% had gon‐ orrhea. Both groups have children with congenital health problems (approximately 6%).

Some of the reported symptoms in the case group were cramps (61%), tiredness and weakness (53%), blurred vision (45%), sweating (45%), tearing (43%), nervousness (38%), dizziness (37%) and tingling in the extremities (37%). According to literature it can be considered that pesticide intoxication is nonspecific and produce the subclinical symptoms identified in the present study in addition to anorexia, insomnia, digestive alterations and itching of skin and mucous [11]. Mostly the symptoms caused by pesticides exposure are diagnosed as common cold or flu [29]. This symptomatology is not produced at the same time because every chemical product acts in a different way and will differ in each of the persons with a chronic exposure. In the present study, during the physical auscultation, the average weight and height in the case group and control group was 82 and 81 kg and 1.72 m, respectively. The vital signs were normal for both groups; 70 and 80 pulsations/min (normal value 70-80 pulsations/min), respiratory rate 20 breaths/min (normal 12-20 breaths /min) and blood pressure 120/180 (normal 120/180).

*Group 2.* Nursing women, description based on surveys. A total of 51 surveys were made to nursing women, 79% of them have been living in this community for more than five years. The average age was 24 years while the median was 23. The highest age was 39 and the low‐ est 16. The average body weight of women was 82 kg (±15.9), with an average height of 1.72 m (±0.07). The average number of children was three, 98% were married (including the ones that live in free union) and only 2% were single (this includes also the ones that are di‐ vorced). The 72% of the women were housewives, but 92% of them mentioned to have worked in agriculture. The 77% of the participants were in contact with pesticides; 69% ap‐ plied in more than one occasion and only 34% used protective clothing while applying (gloves, special clothing for their work and mask).

**Analyses Case group Control group Normal levels\***

*(cells/µL)* 6,966.20 6,664.71 5,000 – 10,000

*(millions of cells/µL)1* 4.96 5.13 4.6 - 6.2

concentration (MCHC) *(%) 2* 33.06 33.52 32 - 36

*(fL)3* 44.39 44.62 35 – 55

**Table 1.** Results of hematic biometry analyses conducted on men exposed to pesticides from Sonora, Mexico

**Table 2.** Levels of blood chemistry test conducted on men exposed to pesticides from Sonora, Mexico

**Analyses Case group Control group Normal levels** Serum glucose *(mg/dL)* 105.38 102 55 - 115 Serum urea *(mg/dL)* 27 27 10 - 50 Creatinin *(mg/dL)* 0.86 0.86 0.7 - 1.2 Cholesterol *(mg/dL)* 195.40 180.05 < 200 Triglycerides *(mg/dL)* 137 131.29 < 150 Total proteins *(g/dL) 1* 7.95 7.5 6.4 - 8.3 Albumin *(g/dL)2* 4.87 4.51 3.5 - 5 Globulin *(g/dL)* 3.09 2.98 2.3 - 3.5 Relation Albumin/Globulin 1.69 1.55 2.5 Total bilirrubin *(mg/dL)3* 0.67 0.93 < 1.1 Alkaline phosphatase *(U/L)4* 106.20 80.31 40 - 129 Cholinesterase *(U/L)5* 968-3940 3,382-8,108 4,300-10,500 Dismutase superoxide *(U/mL)* 273.38 275.08 164 - 240

14.83 15.24 13.5 - 18

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319

Leucocytes

Erythrocytes

Hemoglobin *(g/dL)*

RDW

\* [50].

Mean corpuscular hemoglobin

1p<0.06, 2p<0.04, 3p<0.009.

1p<0.03, 2p<0.0002, 3p<0.039, 4p<0.0013, 5p<0.026.

The 53% applied pesticides in their home; 38% with an annual application, 43% monthly and 19% weekly. Insecticides applied at home were pyrethroids (20%), and organophos‐ phates (14%).

According to the literature, intoxication by pesticides is nonspecific and produce symptoms like: excitability, tremors, sweating, tiredness, dizziness, headache and convulsions; in wom‐ en they can also cause a decrease in the duration of breastfeeding [11]. The symptoms present in the participants of this study were fatigue (70%), headache (62%) and perspiration (46%). Around 76% of women (39 of 51) agreed to donate breast milk, 14% (7 of 51) of the women decided to retire and not to collaborate more in the research and the remaining 10% (5 of 51), were not producing the necessary amount for analysis.

### **3.2. Blood analysis**

Significant differences were observed between both groups (case and control) regarding the number of erythrocytes, mean corpuscular hemoglobin concentration (MCHC), and red blood distribution width (RDW); these values were lower for the case group (Table 1). Re‐ garding the obtained results in the chemical blood analysis, both groups presented levels within the normal values for the measured biochemical indicators. However, it is important to mention that statistical differences were observed between the groups with respect to the concentration of total protein, albumin, alkaline phosphatase, glutamic oxaloacetic transami‐ nase (SGOT or AST) and glutamic pyruvic transaminase (SGPT or ALT); the found levels in the case group were superior to control. In a study performed with pesticide factory work‐ ers exposed to carbamates, organophosphates and organochlorines superior values were ob‐ served in total proteins [30]. However, in studies conducted with experimental animals, total protein values were not altered by the presence of pyrethroid such as cypermethrin, but the albumin levels decreased at the fifth day of intoxication [31]. Some studies per‐ formed to determine the influence of pesticide residue on biochemical indicators have re‐ ported that glucose levels increased after expose experimental animals to malathion (20 µg/mL) and after few hours levels went back to normal [32]. On the other hand, it has been reported that cholesterol and triglycerides levels are inhibited after applying a daily dose of cypermethrin (a pyrethroid insecticide) to Wistar rats [31]. A study referring to the toxico‐ logical effect of polychlorinated biphenyls (PCB's) in fish, reported that PCB's caused lipid peroxidation, increased cholesterol levels in serum and in some species caused hepatic toxic‐ ity and hypertension [33]. Recent studies about the indiscriminate use of pesticides in Tas‐ mania, Australia, have reported effects in the health of its habitants (obesity, hypertension and high cholesterol levels) [34]. Researchers have confirmed that acetylcholinesterase is an indicator of damage by organophosphate and carbamate pesticides [35], in this study the case group mentioned having contact with this substances and the levels of cholinesterase were below normal values. In previous research it was observed that chronic exposure to organophosphate insecticides is related to an increase of catalase, superoxide dismutase and glutathione peroxidase [36]. A study performed in the South India, related to the effect of pesticides on SOD, observed an increase in the levels of this enzyme parallel to the severity of the poisoning with organophosphates [37].


plied in more than one occasion and only 34% used protective clothing while applying

The 53% applied pesticides in their home; 38% with an annual application, 43% monthly and 19% weekly. Insecticides applied at home were pyrethroids (20%), and organophos‐

According to the literature, intoxication by pesticides is nonspecific and produce symptoms like: excitability, tremors, sweating, tiredness, dizziness, headache and convulsions; in wom‐ en they can also cause a decrease in the duration of breastfeeding [11]. The symptoms present in the participants of this study were fatigue (70%), headache (62%) and perspiration (46%). Around 76% of women (39 of 51) agreed to donate breast milk, 14% (7 of 51) of the women decided to retire and not to collaborate more in the research and the remaining 10%

Significant differences were observed between both groups (case and control) regarding the number of erythrocytes, mean corpuscular hemoglobin concentration (MCHC), and red blood distribution width (RDW); these values were lower for the case group (Table 1). Re‐ garding the obtained results in the chemical blood analysis, both groups presented levels within the normal values for the measured biochemical indicators. However, it is important to mention that statistical differences were observed between the groups with respect to the concentration of total protein, albumin, alkaline phosphatase, glutamic oxaloacetic transami‐ nase (SGOT or AST) and glutamic pyruvic transaminase (SGPT or ALT); the found levels in the case group were superior to control. In a study performed with pesticide factory work‐ ers exposed to carbamates, organophosphates and organochlorines superior values were ob‐ served in total proteins [30]. However, in studies conducted with experimental animals, total protein values were not altered by the presence of pyrethroid such as cypermethrin, but the albumin levels decreased at the fifth day of intoxication [31]. Some studies per‐ formed to determine the influence of pesticide residue on biochemical indicators have re‐ ported that glucose levels increased after expose experimental animals to malathion (20 µg/mL) and after few hours levels went back to normal [32]. On the other hand, it has been reported that cholesterol and triglycerides levels are inhibited after applying a daily dose of cypermethrin (a pyrethroid insecticide) to Wistar rats [31]. A study referring to the toxico‐ logical effect of polychlorinated biphenyls (PCB's) in fish, reported that PCB's caused lipid peroxidation, increased cholesterol levels in serum and in some species caused hepatic toxic‐ ity and hypertension [33]. Recent studies about the indiscriminate use of pesticides in Tas‐ mania, Australia, have reported effects in the health of its habitants (obesity, hypertension and high cholesterol levels) [34]. Researchers have confirmed that acetylcholinesterase is an indicator of damage by organophosphate and carbamate pesticides [35], in this study the case group mentioned having contact with this substances and the levels of cholinesterase were below normal values. In previous research it was observed that chronic exposure to organophosphate insecticides is related to an increase of catalase, superoxide dismutase and glutathione peroxidase [36]. A study performed in the South India, related to the effect of pesticides on SOD, observed an increase in the levels of this enzyme parallel to the severity

(gloves, special clothing for their work and mask).

318 Insecticides - Development of Safer and More Effective Technologies

of the poisoning with organophosphates [37].

(5 of 51), were not producing the necessary amount for analysis.

phates (14%).

**3.2. Blood analysis**

**Table 1.** Results of hematic biometry analyses conducted on men exposed to pesticides from Sonora, Mexico


**Table 2.** Levels of blood chemistry test conducted on men exposed to pesticides from Sonora, Mexico

### **3.3. Urine analysis**

The results of the testing performed on urine for both groups were very similar and were within the normal values, it can be indicate that no abnormalities were observed in the cor‐ poral fluid that can be attributed to pesticide exposure. Besides, no statistical differences were observed amongst the study group (Table 3).

**Analyses Case group Control group Normal levels\***

30.30% 7.14%

24.24% -

100% (normal) Opalescent gray

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Insecticide Residuality in Mexican Populations Occupationally Exposed

color (normal)

*(mL)1* 2.48 3.73 "/> 2 pH*<sup>2</sup>* 8.05 8.35 7.2 – 8.0

> 96.55% (normal) 3.45% (anormal, yellow color)

Liquefaction 6.9% (normal) Normal

*(Filament bigger than 2 cm)* 44.83% (normal) 28.57% (normal)

Sperm viability 45% 75% Sperm fast progressive motility 42.5% 52.80% Sperm slow progressive motility 16.88% 21.07% Sperm mobility 57.13% 28.93% Bacteria 12% 7%

Normal sperm morphology 41.08% 75.92%

**Table 4.** Results of semen analysis conducted on men exposed to pesticides from Sonora, Mexico

**Table 5.** Organophosphate pesticide residues in biological fluids of field workers from Sonora, Mexico

**Table 6.** Organochlorine pesticide residues in biological fluids of field workers from Sonora, Mexico

**Biological fluid p,p'-DDT p,p'-DDE p,p'-DDD** Semen1 27.3 36.4 36.4 Blood2 0 15.2 3 Urine3 5.5 9.1 14.5

**Biological fluid Diazinon Chlorpyrifos Malathion Parathion** Semen1 17.6 32.3 53 44 Blood2 0 9.1 0 9.1 Urine3 0 9.1 5.5 20

Volume

Viscosity

Aspect

Germinal cells *(Dentritus)*

espermatozoides

1n=11, 2n=33, 3n=55

1n=11, 2n=33, 3n=55.

\* [26].

Specific sperm agglutination

1p<0.03, 2p<0.01, 3p<0.0201, 4p<0.0305.


**Table 3.** Results of microscopic analyses of urine conducted in men exposed to pesticides from Sonora, Mexico

#### **3.4. Semen analysis**

Mostly all the differences between groups (case and control) were observed in the semen analyses. In table 4, it can be observed that the case group presented a lower volume, pH, sperm viability, fast and slow progressive motility and abnormalities in sperm mor‐ phology (spermatozoa macrocephalia, microcephalia, pyriform, band-like, pin-shaped, double head, tail coiled cytoplasmic droplets and amorphous). Additionally, this same group had a higher viscosity and immobility of spermatozoa. In previous studies [6], it was observed that liquefaction was affected by 32% in insecticide applicators, while the present study did not show abnormalities or significant differences between groups. In this study we observed that in the controls there were more live sperm (one third more than the majority of the cases). The percentage of the abnormalities detected in the present study was superior represented by a 35% that the one found in the control group, comparing this result with the study regarding the insecticide applicators in Her‐ mosillo, Sonora, there was a similar behavior [6].


1p<0.03, 2p<0.01, 3p<0.0201, 4p<0.0305.

\* [26].

**3.3. Urine analysis**

Leucocytes *(cells/field)*

Amorphous salts

**3.4. Semen analysis**

were observed amongst the study group (Table 3).

320 Insecticides - Development of Safer and More Effective Technologies

Calcium oxalate crystals 20% (abundant)

Epithelial cells 95% (poor)

mosillo, Sonora, there was a similar behavior [6].

The results of the testing performed on urine for both groups were very similar and were within the normal values, it can be indicate that no abnormalities were observed in the cor‐ poral fluid that can be attributed to pesticide exposure. Besides, no statistical differences

2 2

25% (abundant) 25% (moderate)

57.14% (abundant) 28.57% (poor) 14.29% (moderate)

87.5% (poor) 12.5% (moderate)

**Analyses Case group Control group**

Uric acid crystals 53.33% (poor) 25% (moderate)

Bacteria 80.77% (poor) 54.55% (poor)

Mucine 59% (poor) 75% (moderate)

**Table 3.** Results of microscopic analyses of urine conducted in men exposed to pesticides from Sonora, Mexico

Mostly all the differences between groups (case and control) were observed in the semen analyses. In table 4, it can be observed that the case group presented a lower volume, pH, sperm viability, fast and slow progressive motility and abnormalities in sperm mor‐ phology (spermatozoa macrocephalia, microcephalia, pyriform, band-like, pin-shaped, double head, tail coiled cytoplasmic droplets and amorphous). Additionally, this same group had a higher viscosity and immobility of spermatozoa. In previous studies [6], it was observed that liquefaction was affected by 32% in insecticide applicators, while the present study did not show abnormalities or significant differences between groups. In this study we observed that in the controls there were more live sperm (one third more than the majority of the cases). The percentage of the abnormalities detected in the present study was superior represented by a 35% that the one found in the control group, comparing this result with the study regarding the insecticide applicators in Her‐

26.67% (moderate)

50% (abundant) 37.5% (poor) 12.5% (moderate)

5% (moderate)

**Table 4.** Results of semen analysis conducted on men exposed to pesticides from Sonora, Mexico


1n=11, 2n=33, 3n=55

**Table 5.** Organophosphate pesticide residues in biological fluids of field workers from Sonora, Mexico


1n=11, 2n=33, 3n=55.

**Table 6.** Organochlorine pesticide residues in biological fluids of field workers from Sonora, Mexico

#### **3.5. Association of exposure indicators**

In the regression analysis a relationship was observed between biochemical indicators and pes‐ ticide exposure time. The biochemical indicators involved were erythrocytes, mean corpuscu‐ lar volume, red blood distribution width and urea. For every year of pesticide exposure there was a decrement of 0.082 million of erythrocytes and 0.088 fL of VCM. For every year of pesti‐ cide exposure there was an increment of 0.134 fL RDW and 0.163 mg/ dL of urea. In a research performed in Spain with workers chronically exposed to pesticides, the affected biochemical indicators were urea, TGO enzymes and lactate dehydrogenase (LDH) [38]. In the figure 1, there are the associations studied between biochemical indicators and pesticides exposure time. It is important to mention that the determination of cholinesterase in this study was car‐ ried out using butyrylcholinesterase or plasma cholinesterase. In previous studies cholinester‐ ase was associated with other biochemical indicators. The results showed that it bound to cholesterol, triglycerides and others as transaminases [38]. This was not possible to observe in the present study, due to the difference on diet and alcohol consumption.

p,p'-DDE, 39% p,p'-DDD and 20% p,p'-DDT. Regarding the organophosphate insecticides analyzed 52% had parathion, 28% chlorpyrifos, 14% malathion and 7% parathion.The high‐ est concentration found was 7.1 µg/L of p,p'-DDE in serum and 6.4 µg/L of p,p'-DDD in urine. The highest concentration found in semen was 2.3 µg/L of p,p'-DDE. Regarding the organophosphate insecticides (chlorpyrifos, malathion and parathion) in the field workers urine the highest concentration were 3.4, 2.2 y 2.0 µg/L, respectively. This levels were con‐

Insecticide Residuality in Mexican Populations Occupationally Exposed

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323

*Breast milk*. There was not detected DDT and DDT metabolites in 85.6% of breast milk sam‐ ples. Although, 15.4% of samples had p,p'-DDT, p,p'-DDD and p,p'-DDE residues. The most persistent metabolite was p,p'-DDE due to its stability amongst the DDT metabolites [40-42]. The highest level found in breast milk was 9.0 µg/kg (p,p'-DDE) and the lowest level was 0.1 µg/kg (p,p'-DDT). It is important to mention that the infants fed with this contaminated breast milk were in the range of 2-6 month old and their diet was based exclusively on breast milk. Although, according to the American Academy of Pediatrics [43], from the six months onwards, milk is substituted by solid. Other author [44], mentions that breast milk is the primary route where the infants are expose to certain lipophilic toxics that are accumu‐ lated by decades in the maternal adipose tissue. If we compare the residues found in this study with the highest levels found in other studies, like the ones reported in [40] for DDE (1.06 mg/kg), and DDT (1.11 mg/kg) in breast milk. The same happened by comparing them with similar works performed in Veracruz with p,p'-DDT and p,p'-DDE (1.27 y 5.02 mg/kg, respectively) [42], and those in the peripheral zone of Mexico City [41], were 108 samples of human milk were analyzed. The content of p,p'-DDT found was 0.117 mg/kg and for p,p'- DDE 2.31 mg/kg. The decrease in the values found was associated to a possible restriction in the use of DDT, although the presence of p,p'-DDE is evident. Specifically, the studies per‐ formed in Pueblo Yaqui (Sonora) [45] in breast milk, found levels of p,p'-DDE disturbingly high (6.25 mg/kg), considering that is one of the most important agricultural areas in Mexi‐ co. At the present time, in the same zone, the authors reported the presence of p,p'-DDE in 66.66% of the samples of serum from children (between 6 and 12 years of age), with the lev‐ els of 0.1 a 443.9 µg/L [46]. These results suggest that DDT is present in the environment and the residues found in biological samples could be due to many factors such as contaminated food consumption. In the present study, the most frequent found metabolite in biological samples was p,p´-DDE due to a its degradation by enzyme system in mammals. According to literature, 50% of p,p'-DDT in the environment could be degrade in 6 years, 67% in 12 years being p,p'-DDE the only product for its degradation [11]. Therefore the contamination present in the studied breast milk can be due to an exposition for more than 12 years. The World Health Organization [47] reports maximum residue limits in foods for DDT and its metabolites of 1.25 mg/kg. While the levels of tolerance established by the FAO/WHO in 1998 [48] for the same compounds in cow milk are 0.05 mg/kg fatty base, in the present study the found levels in breast milk were below the established levels (less than 82%). It is important to mention that DDT levels and other organochlorine compounds in breast milk could be different based on the number of births, age and other factors such as diet, occupa‐ tion and social status [49, 40]. It is known that levels of these compounds are higher in the breast milk from younger women. In this research, it not was possible to find a correlation

sidered lower in relation to other studies [39].

**Figure 1.** Correlations of blood analyses for case group

#### **3.6. Determination of insecticides and corporal fluids**

*Blood, urine and semen*. A total of 103 samples were analyzed: 73 (71%) were positive to some pesticide. Around 44 (60%) had organochlorine insecticides residues and 29 (40%) had orga‐ nophosphorus insecticides residues. The organochlorine insecticides detected were 41% p,p'-DDE, 39% p,p'-DDD and 20% p,p'-DDT. Regarding the organophosphate insecticides analyzed 52% had parathion, 28% chlorpyrifos, 14% malathion and 7% parathion.The high‐ est concentration found was 7.1 µg/L of p,p'-DDE in serum and 6.4 µg/L of p,p'-DDD in urine. The highest concentration found in semen was 2.3 µg/L of p,p'-DDE. Regarding the organophosphate insecticides (chlorpyrifos, malathion and parathion) in the field workers urine the highest concentration were 3.4, 2.2 y 2.0 µg/L, respectively. This levels were con‐ sidered lower in relation to other studies [39].

**3.5. Association of exposure indicators**

322 Insecticides - Development of Safer and More Effective Technologies

**Figure 1.** Correlations of blood analyses for case group

**3.6. Determination of insecticides and corporal fluids**

*Blood, urine and semen*. A total of 103 samples were analyzed: 73 (71%) were positive to some pesticide. Around 44 (60%) had organochlorine insecticides residues and 29 (40%) had orga‐ nophosphorus insecticides residues. The organochlorine insecticides detected were 41%

In the regression analysis a relationship was observed between biochemical indicators and pes‐ ticide exposure time. The biochemical indicators involved were erythrocytes, mean corpuscu‐ lar volume, red blood distribution width and urea. For every year of pesticide exposure there was a decrement of 0.082 million of erythrocytes and 0.088 fL of VCM. For every year of pesti‐ cide exposure there was an increment of 0.134 fL RDW and 0.163 mg/ dL of urea. In a research performed in Spain with workers chronically exposed to pesticides, the affected biochemical indicators were urea, TGO enzymes and lactate dehydrogenase (LDH) [38]. In the figure 1, there are the associations studied between biochemical indicators and pesticides exposure time. It is important to mention that the determination of cholinesterase in this study was car‐ ried out using butyrylcholinesterase or plasma cholinesterase. In previous studies cholinester‐ ase was associated with other biochemical indicators. The results showed that it bound to cholesterol, triglycerides and others as transaminases [38]. This was not possible to observe in

the present study, due to the difference on diet and alcohol consumption.

*Breast milk*. There was not detected DDT and DDT metabolites in 85.6% of breast milk sam‐ ples. Although, 15.4% of samples had p,p'-DDT, p,p'-DDD and p,p'-DDE residues. The most persistent metabolite was p,p'-DDE due to its stability amongst the DDT metabolites [40-42]. The highest level found in breast milk was 9.0 µg/kg (p,p'-DDE) and the lowest level was 0.1 µg/kg (p,p'-DDT). It is important to mention that the infants fed with this contaminated breast milk were in the range of 2-6 month old and their diet was based exclusively on breast milk. Although, according to the American Academy of Pediatrics [43], from the six months onwards, milk is substituted by solid. Other author [44], mentions that breast milk is the primary route where the infants are expose to certain lipophilic toxics that are accumu‐ lated by decades in the maternal adipose tissue. If we compare the residues found in this study with the highest levels found in other studies, like the ones reported in [40] for DDE (1.06 mg/kg), and DDT (1.11 mg/kg) in breast milk. The same happened by comparing them with similar works performed in Veracruz with p,p'-DDT and p,p'-DDE (1.27 y 5.02 mg/kg, respectively) [42], and those in the peripheral zone of Mexico City [41], were 108 samples of human milk were analyzed. The content of p,p'-DDT found was 0.117 mg/kg and for p,p'- DDE 2.31 mg/kg. The decrease in the values found was associated to a possible restriction in the use of DDT, although the presence of p,p'-DDE is evident. Specifically, the studies per‐ formed in Pueblo Yaqui (Sonora) [45] in breast milk, found levels of p,p'-DDE disturbingly high (6.25 mg/kg), considering that is one of the most important agricultural areas in Mexi‐ co. At the present time, in the same zone, the authors reported the presence of p,p'-DDE in 66.66% of the samples of serum from children (between 6 and 12 years of age), with the lev‐ els of 0.1 a 443.9 µg/L [46]. These results suggest that DDT is present in the environment and the residues found in biological samples could be due to many factors such as contaminated food consumption. In the present study, the most frequent found metabolite in biological samples was p,p´-DDE due to a its degradation by enzyme system in mammals. According to literature, 50% of p,p'-DDT in the environment could be degrade in 6 years, 67% in 12 years being p,p'-DDE the only product for its degradation [11]. Therefore the contamination present in the studied breast milk can be due to an exposition for more than 12 years. The World Health Organization [47] reports maximum residue limits in foods for DDT and its metabolites of 1.25 mg/kg. While the levels of tolerance established by the FAO/WHO in 1998 [48] for the same compounds in cow milk are 0.05 mg/kg fatty base, in the present study the found levels in breast milk were below the established levels (less than 82%). It is important to mention that DDT levels and other organochlorine compounds in breast milk could be different based on the number of births, age and other factors such as diet, occupa‐ tion and social status [49, 40]. It is known that levels of these compounds are higher in the breast milk from younger women. In this research, it not was possible to find a correlation between the presence of pesticides residues in breast milk with age, number of children and occupation; this due to a this studied group did not have the necessary characteristics to de‐ termine the possible correlations.

**Author details**

sillo, Sonora, México

gust 2012).

2002. p371-388.

2011;4(2) 70-81.

Toxicology 2012;(88) 828-832.

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Fabiola-Gabriela Zuno-Floriano2

María-Lourdes Aldana-Madrid1\*, María-Isabel Silveira-Gramont1

\*Address all correspondence to: laldana@guayacan.uson.mx

,

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and Guillermo Rodríguez-Olibarría1

1 Departamento de Investigación y Posgrado en Alimentos, Universidad de Sonora. Hermo‐

2 Department of Environmental Toxicology, University of California, Davis, California, USA

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