*2.2.9 Analysis of results in relation to the content of lead and cadmium in the runoff water (mg/kg)*

Ho: There are no differences in Pb and Cd between sampling groups.

H1: There are differences in Pb and Cd between sampling groups.

In the ANOVA, the significance values are 0.887 (Pb) and 0.813 (Cd), a result obtained from comparing selected groups A, B, and C, respectively, according to the heavy metal content of lead and cadmium in the runoff water of fields of production from granadilla fruit (*P. ligularis*) according to intensity of use of agrochemicals. These values are greater than the significance of α = 0.05; therefore the statistical decision in this regard is to accept the null hypothesis; consequently, the alternative hypothesis is rejected, concluding that there is sufficient evidence to affirm that there are no significant differences in lead and cadmium content in runoff water samples at different intensity of application of agrochemicals at a confidence level of 95% (see **Table 9**).

*2.2.10 Analysis of results in relation to the copper content in the runoff water (mg/kg)*


Ho: There are no differences in Cu between sampling groups. H1: There are differences in Cu between sampling groups.

*Source: Data processed from chemical analysis Laboratory UNMSM 2019.*

#### **Table 9.**

*ANOVA of comparison between groups of lead and cadmium content in runoff water in granadilla fruit (*Passiflora ligularis*) cultivation, according to the intensity of use of agrochemicals.*


#### **Table 10.**

*ANOVA of comparison between groups of copper content in runoff water in the cultivation of granadilla (*Passiflora ligularis*), according to the intensity of use of agrochemicals.*

In the ANOVA, the significance value is 0.622, a result obtained from comparing selected groups A, B, and C, respectively, according to the heavy metal content of copper in the runoff water from the granadilla fruit production fields (*P. ligularis*) according to intensity of use of agrochemicals. Said value is greater than the significance of α = 0.05; therefore the statistical decision in this regard is to accept the null hypothesis; consequently, the alternative hypothesis is rejected, concluding that there is sufficient evidence to affirm that there are no significant differences in copper content in runoff water samples at different intensity of application of agrochemicals at a confidence level of 95% (see **Table 10**).

#### **2.3 Discussion**

Next, you perform the comparison of the content and concentration of heavy metals between sampling groups (A, B, and C) according to intensity of application of agrochemicals in the agricultural management of granadilla (*P. ligularis*), Oxapampa district.

The average results obtained for heavy metals in the fruits were: in the sectors of AcAf SA1Bf, PaCf between 0.26 and 0.36 mg of Cu/kg; (Ch2Af, Ab3Bf ARP3Cf, QllAf, Ch3Bf, SA2Cf) between 0.001 and 0.003 mg of Cd and Pb/kg; (Ab1Af, CaBf, ARP1Cf, Ch1Af, Ab2Bf, ARP2Cf) between 0.0012 and 0.0006 mg of As and Hg/kg. In soils: in the sectors of AcAs SA1Bs, PaCs, between 19 and 25 mg of Cu/kg; (Ch2As, Ab3Bs ARP3Cs, QllAs, Ch3Bs, SA2Cs) between 0.02 and 0.08 mg of Cd and Pb/kg; (Ab1As, CaBs, ARP1Cs, Ch1As, Ab2Bs, ARP2Cs) between 0.05 and 0.08 mg of As and Hg/kg. For the runoff waters: in the sectors of AcAa SA1Ba, PaCa, between 1 and 1.12 mg of Cu/kg; (Ch2Aa, Ab3Ba ARP3Ca, QllAa, Ch3Ba, SA2Ca) between 0.002 and 0.003 mg of Cd and Pb/kg; (Ab1Aa, CaBa, ARP1Ca, Ch1Aa, Ab2Ba, ARP2Ca) between 0.002 and 0.005 mg of As and Hg/kg.

These results show high levels of risk in human health and the environmental contamination in the agroecosystems of the district of Oxapampa, whose main cause is lack of technical advice from state agencies and coupled with this a nontechnical dosage of pesticides and fertilizers, chemicals, agrochemicals, applied by farmers in the production of granadilla fruit.

The average results obtained for heavy metals in fruits are shown below in **Table 11**, where the Provisional Tolerable Weekly Intake (PTWI) values [9] are also shown, in mg/kg of body weight for the same heavy metals, in order to observe that there is a toxicological risk related to a weekly consumption of these fruits.

It has been preferred to use the PTWI and not the maximum levels (ML), since this toxicological result is appropriate for food contaminants, such as heavy metals, due to *Environmental Pollution Originated by the Excessive Use of Agrochemicals… DOI: http://dx.doi.org/10.5772/intechopen.104910*


#### **Table 11.**

*Comparison of the average experimental results with the PTWI of heavy metals in food.*

their cumulative capacity. The PTWI by definition is a value that represents the permissible weekly human exposure to such contaminants.

These results are comparable with those obtained in other investigations such as the studies by Fang and Zhu, who showed concentrations of five heavy metals (chromium, copper, cadmium, mercury, and lead) in four fruits (pear, grape, peach-shaped plum, and orange), which exceeded safety standards. They state that the origin of these metals was mainly due to the application of foliar fertilizers, ripening agents, fungicides, and pesticides during flowering and ripening [10]. Shaheen et al. used inductively coupled plasma mass spectrometry (ICP-MS) and demonstrated the presence of toxic heavy metals such as As, Cd, Pb, Cr, Mn, Ni, Cu, and Zn in representative samples of fruits and vegetables in Bangladesh. These results exceeded the maximum permissible concentration (MAC) established by the FAO/WHO for Pb in mango and Cd in tomato among the fruits and vegetables analyzed, representing risks to human health [11].

Other researchers such as Abbasi et al. also evaluated the concentration of heavy metals and associated health risk in processed fruit products sold in local markets in northern Pakistan. They quantified seven metals: cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), lead (Pb), and zinc (Zn) in different food samples and showed that measured levels of these metals varied significantly and were relatively higher than their allowable limits. Univariate and multivariate analysis yielded a strong association between Cr, Co, Pb, and Fe and confirmed heavy metal contamination through natural and anthropogenic sources in processed foods [12].

Likewise, Marini et al. evaluated the daily intake in various foods of four heavy metals, such as cadmium, mercury, lead, and arsenic; and four minerals: chromium, nickel, selenium, and zinc. The risk of exceeding the provisional tolerable daily intake in the four proposed Danish dietary profiles was on average 60%, 17%, and 16% for cadmium, mercury, and lead, respectively. For total arsenic, the risk of exceeding the provisional daily intake was 33%, and they emphasize the importance of implementing measures to reduce the risk cycle of heavy metals that threaten environmental health and food safety [13], showing a relationship with the results obtained in this work.

As will be seen later, the results obtained in the investigation agree with other studies, in which they also demonstrated that the contaminated water used for growing vegetables has contaminated the soil and that the samples of water, soil, and vegetables were contaminated with Ni, Cd, Cr, Cu, Pb, and Zn, and the concentration trends of these metals were as follows: 0,613 > 0,316 > 0,162 > 0,065 > 0,041 >


#### **Table 12**.

*Concentration of heavy metals: Pb, As. Cd, Cu, and Hg in runoff water and water collected in the cattle town of Chontabamba – Oxapampa [16].*

0,028 mL/L for Ni, Cd, Pb, Cr, Cu, and Zn, respectively, in the contaminated water and 189,09 > 125 > 104,92 > 41,85 > 28,58 > 21,72 for Zn, Cr, Ni, Pb, Cu, and Cd mg/kg in the soil, which represents a risk to the health of the population [14, 15].

**Table 12** shows the concentrations of heavy metals: Pb, As. Cd, Cu, and Hg, obtained by this research in runoff water in the granadilla fruit (*P. ligularis*) cultivation fields and the concentrations of water destined for livestock activity for dairy animal consumption in the location of Chontabamba [16].

**Table 12** shows the results obtained by Bernal from the analysis of water from broken, rivulets that originate from wetlands, groundwater, and that are relatively protected by natural forest areas, and that correspond to areas dedicated only to livestock, where no As, Cd, and Cu are detected, while Hg and Pb present relatively low levels. Compared with the results of the study for this water factor, an impact on runoff water contamination is observed, which would be related to the use of agrochemicals in granadilla fruit (*P. ligularis*) crops and the consequent risk to human health.

**Table 13** shows the contents of heavy metals in the grazing soil of the dairy herds analyzed in samples from the localities of Chontabamba and Oxapampa [16] and the concentrations of these heavy metals obtained by the study in the soils intended for the cultivation of granadilla (*P. ligularis*).

In **Table 13** it can be seen how the concentrations of heavy metals present in the soils destined for livestock, downstream of the soils destined for the cultivation of granadilla show a higher concentration of heavy metals in arsenic, mercury, lead, and cadmium with the exception of copper, where its value is small compared with the soil for granadilla fruit that has a high concentration, which corroborates the hypothesis that the excessive use of agrochemicals would be the cause of these negative environmental impacts and that they represent a risk to human health.


#### **Table 13**.

*Concentration of heavy metals: Pb, As, Cd, Cu, and Hg, in the soil of granadilla fruit (*Passiflora ligularis*) cultivation and soil of the cattle town of Chontabamba and Oxapampa [16].*

#### *Environmental Pollution Originated by the Excessive Use of Agrochemicals… DOI: http://dx.doi.org/10.5772/intechopen.104910*

The studies carried out by other authors corroborate the results obtained in this investigation, agreeing when mentioning that there are differences between the different managements studied, evidencing that in those intensively used soils, the highest values were recorded for Cu2<sup>+</sup> and Pb2<sup>+</sup> while in the case of Cd2<sup>+</sup> , the agricultural management system presented the highest content, reaching a value higher than the maximum permissible limit of several countries [17]. On the other hand, it is also mentioned that that the coefficient of variation of the analyzed metal content indicates that the values are dispersed in a range average: copper from 0.007 to 0.053, cadmium from 0.013 to 0.070, and lead from 0.010 to 0.064 [18].

From the results of the statistical analysis by ANOVA of comparison between groups according to intensity of use of agrochemicals (A, B, and C) for soil samples obtained from the production fields of *P. ligularis* of the selected farmers, it is found that the heavy metals found such as arsenic, lead, cadmium, and copper, according to hypothesis testing, it was shown that there is no significant difference in the concentrations of these heavy metals in soils. However, in the case of mercury concentration, it did show significant differences between the groups of samples that were analyzed. These results indicate that the contamination of the soil by these chemical elements is limiting the quality of the agricultural products of Oxapampa. In this regard, they point out that the high proportion of Pb is a potential bioavailable contaminant that can interfere with the development of crops and that can be incorporated into the different levels of the food chain until reaching human beings.

On the other hand, from the analysis by ANOVA of comparison between groups of samples selected according to intensity of use of agrochemicals, for heavy metals such as arsenic, mercury, lead, cadmium, and copper that were found and analyzed in the runoff water of the granadilla fruit (*P. ligularis*) production fields, the hypothesis that there is no significant difference in the concentration of these chemical elements was demonstrated, the same ones that agree with the results obtained by Pérez [18].

Finally, from the ANOVA analysis of comparison between groups according to the intensity of use of agrochemicals (A, B, and C) for samples of granadilla (*P. ligularis*) fruits from the fields of the selected farmers, the heavy metals found that such as arsenic, mercury, lead, and copper and according to the verification of hypotheses, it was shown that there is no significant difference in the concentrations of said heavy metals. However, in the case of the concentration of cadmium, it did show significant differences between the groups of samples analyzed. This statistical procedure carried out is reinforced by mentioning that through the analysis of variance of one factor (ANOVA), the comparison tests serve to evaluate the behavior of the experimental data obtained in the analysis [19].
