**1.5. Excretion**

and approach of arsenic from the approach of environmental nutrition and food security, and water can be triggers for a new and different way of decrease the damage to the health with

*"Time to give focus to public health and with it the promotion of food security as a strategy to mitigate* 

Arsenic is a metalloid that can be found naturally in the Earth, mainly in the Earth's crust, and can leak into the groundwater reserves. In many countries of the world, groundwater represents the main source of drinking water; therefore, exposure to arsenic from drinking water is considered a public health problem [8, 9]; not only the direct consumption of water contaminated with arsenic is a factor of exposure but also indirect consumption through food, when water is used in the preparation of food, in the irrigation of fields, and for consumption

The World Health Organization (WHO) and the guidelines of the Environmental Protection Agency (EPA) of the United States, established an allowed limit of 0.01 mg/L for arsenic in drinking water [11]. The Ministry of Health of Mexico establishes an allowable limit of 0.05 mg/L of arsenic in drinking water [11, 12], with current modifications at 0.025 mg/L,

To study and know the toxicity of the metalloid, must be made of the speciation of it, but also of the physiological conditions of the exposed population (age, body surface, nutritional status, etc.), which will be addressed in this chapter. Arsenic compounds are classified into three groups: (1) The inorganic arsenic compounds; (2) Organic compounds, and (3) Gaseous compounds; they are usually in their trivalent and pentavalent state. The most common trivalent inorganic arsenic compounds are arsenic trioxide, arsenic trichloride, and sodium arsenic; the most common pentavalent inorganic arsenic compounds are arsenic pentoxide, arsenic acid, and arsenate; and the organic arsenic compounds are monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) [13, 14]. The level of toxicity of arsenic depends on its valence and its organic or inorganic form. Organic arsenic is considered less toxic than inorganic as it is easier to excrete. The inorganic arsenic is the most toxic form of As, in its trivalent form it can combine chemically with the sulfhydryl groups, which are organic compounds that contain a sulfur atom as a functional group attached to a hydrogen (-SH), these functional groups form inter- and intramolecular bridges in proteins and their structure and biological function depend on them.

Arsenic can be incorporated into the body by ingestion, inhalation or through the skin, more than 90% of the ingested arsenic is absorbed in the gastrointestinal tract. Organic arsenic is easier to excrete and is usually found mainly in meat, seafood, and some cereals. The ability of trivalent arsenic (AsIII) to join groups -SH, confers that toxic capacity while pentavalent arsenic (AsV) interferes with phosphorylation reactions, due to its similarity chemical with

the different pollutants:

*the effects and risks to health"*

44 Arsenic - Analytical and Toxicological Studies

**1.2. Arsenic: food and water security**

of animal, is an exposure factor [10].

**1.3. Metabolism**

**1.4. Absorption**

which are still above international standards.

The excretion of As is variable among people; it will depend on the time and dose of exposure to As, as well as the efficiency of the methylation reactions [8]. It is known that the ability to meet arsenic is saturated when the ingestion exceeds 0.5 mg/d [16]. The main metabolites found in urine after acute or chronic exposure to arsenic are inorganic arsenic, MMA and DMA [8, 17], residual As can also be found in keratinized tissues (skin, hair, and nails), where the presence of arsenic in these tissues has a significant association with chronic exposure to metalloid [15]. Although in general, the presence of arsenic in urine is considered an indicator of acute exposure, it has been found that in prolonged exposures arsenic levels in urine are maintained and increase [8].

That is why the presence of arsenic in urine is considered a reliable marker of chronic exposure to As. It is known that the usual consumption of arsenic varies between 5 and 25 μg/d, and the excretion of arsenic in urine is usually less than 25 μg in 24-hour urine. It has been reported that after a consumption of seafood products, the concentration of arsenic in urine can increase to 300 μg in 24 hours, however, this concentration will decrease after 1 day to <25 μg in 24-hour urine [18]. An excretion rate greater than 1000 μg in 24-hour urine is a sign of significant exposure to As [19, 20].

#### **1.6. Effects of acute and chronic exposure: signs and symptoms**

Chronic exposure to inorganic arsenic causes, mainly, skin lesions, cancer of the bladder, kidney, lungs, and liver. Keratosis and changes in skin pigmentation are recognized signs of chronic exposure to arsenic, while melanosis is a sign associated with acute exposure [8, 21]. Cumulative doses in adults of 0.10 mg/kg/d are related to signs of chronic intoxication and usually appear after 2–8 weeks of exposure. It also causes alterations in intestinal epithelial tissue, decreased production of red and white blood cells, central nervous system involvement, liver damage, and kidney damage [17, 22–24]. The acute lethal dose of arsenic in humans has been estimated at 0.6 mg/kg/day [25].

group, and 2.49% in the control group (p = 0.0199), as well as an increase in the rate of DMA

Food and Water Security as Determinants of the Mitigation of Health Risks…

http://dx.doi.org/10.5772/intechopen.76977

47

Zablotska et al. [32] studied 11,746 people over 18 years of age and found that consumption of riboflavin, pyridoxine, vitamin A, C, and E, and folic acid significantly modified the effects of arsenic exposure. Participants in the highest percentile of consumption of each nutrient (≥1.17 mg/d of riboflavin, ≥4.19 mg/d of pyridoxine, ≥351.61 μg/d of folic acid, ≥7113.06 mg/d of vitamin C, and ≥ 6.41 mg/d of vitamin E), showed a reduction in the risk of lesions derived from exposure to arsenic in 46–68% (p < 0.05). This reflects that the consumption of these key nutrients not only increase the excretion of arsenic, but also the reduction of adverse effects derived from exposure to As. In addition, it has been observed that the concentration of selenium in blood, which is an essential trace element required for the synthesis of several proteins, is inversely related to the risk of pre-malignant lesions in the skin, finding an inversely proportional relationship (p = 0.03) between the concentration of selenium in blood and arsenic in urine [8].

In addition to the above, a poor nutritional status, mainly malnutrition, correlates with the development of skin lesions caused by arsenic poisoning. In 2007 Maharjan et al. [33] developed a study in the adult population (n = 539) where an increase in the risk of manifesting skin lesions due to the arsenic exposure was found 1.65 times more in subjects with a body

(p < 0.05). In addition, it has been described that the decrease in BMI is also a non-specific manifestation of chronic exposure to high concentrations of arsenic (daily arsenic intake of 30 μg/kg/d). In rural populations, a low BMI is a reflection of a poor nutritional status, which is associated with a low intake of certain nutrients, including antioxidants, and nutrients whose poor ingestion has been related to increased production of MMA, the toxic form of

During 2002–2003, the State Public Health Laboratory of Guanajuato found, in two communities of the state, San Agustín of the municipality of Irapuato and Cútaro in Acámbaro, amounts of arsenic in well water (0.950 and 0.109 mg/L, respectively), greater than the permissible limits established by the WHO, and the Secretary of Health of Mexico. These communities have been studied for several years, adding other populations, where this metalloid has also been found.

Next, in **Table 2**, a chronology of the studies published and in the process of publication is presented. The first studies were based on identifying a relationship between the consumption of water contaminated with arsenic and the presence of arsenic in the hair of children living in two communities, which had a relationship (n = 55, p < 0.0001) [35]. In addition, a survey of mothers of children of the previous study revealed that 90–94% of them use well water for different culinary preparations such as broths, soups or beans, even with the knowledge that this source of water is contaminated with arsenic, according to the participants, this

) compared to those with a normal BMI

excretion (p = 0.099), folic acid participates in methylation reactions [30, 31].

mass index (BMI) per below normal (16.5–17.1 kg/m<sup>2</sup>

arsenic, and a low production of DMA [30, 31, 34].

**1.8. Evidence in Guanajuato, Mexico: food and water security**

is done for lack of economic resources to acquire drinking water [10].

Exposure to arsenic generates oxidative stress, and this represents the main mechanism by which arsenic generates multi-organ damage, there are free radical formation directly and also inhibitory effects on antioxidant components [23]. An alteration in the metabolism of GSH secondary to the union of arsenic with -SH groups has been found, as well as the elevation of genes associated with oxidative stress such as heme oxygenase-1 and metallothioneins, after chronic exposure to arsenic [17, 26]. Chronic exposure to arsenic causes an increase in the production of reactive oxygen species (ROS) and an alteration in defense mechanisms against the pro-oxidative effect of ROS, mainly the catalase enzyme (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) [23].
