# Assessment of Pesticide Contamination of Groundwater from Titu-Sarata Plain, Romania
## 1 Introduction  
Pesticides are chemicals that are widely used in agriculture in order to manage pests, breeds, plant diseases or pathogens. Their use helps to reduce and even prevent crop losses and maintain a high quality of agricultural products [1, 2, 3]. Pesticides are also used in homes, offices, shops, and public spaces to control infestations of insects and disease carriers such as mosquitoes, ticks, and rodents [3, 4]. Due to their complex chemical structures and the effects on different species, pesticides can be grouped in several ways. One common method of categorization is based on the type of pest they target. Based on this criterion, pesticides include herbicides, insecticides, fungicides, nematicides, rodenticides or raticides, acaricides, and others [5, 6]. Secondly, based on their origin and chemical composition, most pesticides are either natural or synthetic organic compounds [7]. The toxicity of pesticides depends on several factors, such as their chemical structure and the quantity that is used. The excessive use of pesticides in the past, the lack of appropriate equipment, and the lack of specialized understanding from farmers has led to the contamination of soil, groundwater, and surface water. According to EUROSTAT data, starting from 2011, the consumption of pesticides has declined by 17.36% in the European Union and by 20% in Romania [7]. The harmful environmental effects of pesticide use vary according to their toxicity level, selectivity, and persistence. An important factor that contributes to environmental pollution is the dispersion of pesticides over very long distances and their accumulation in biomass, water, or soil [8]. Pesticides can also affect human health, especially in cases of prolonged or uncontrolled exposure. Long-term exposure to pesticides can disrupt the functionality of the nervous, endocrine, renal, cardiovascular, and respiratory systems, etc. These disruptions have been associated with an increasing incidence of chronic diseases, including cancer, Parkinson's disease, Alzheimer's disease, multiple sclerosis, diabetes, chronic cardiovascular, renal diseases, and others [9]. Since 1991, the use of pesticides has been strictly regulated by EU legislation [7] to protect human health and the environment. Even pesticides with low toxicity can have a negative impact on water quality, soil health, biodiversity, and ecosystems [7]. Although the use of pesticides is strictly regulated to minimize their impact on human health and the environment, there are serious concerns about the health risks associated with the consumption of food and drinking water that has been contaminated with pesticide residues [3; 4; 10; 11]. Pesticides might be present in the environment even if the concentrations are shown to be below the limit of quantification (LOQ) or limit of detection (LOD), but the presence of several pesticides can generate cumulative effects with a significant ecological impact [12]. Pesticides can reach the air, water, and soil through various transfer processes, including adsorption, leaching, and volatilization [13]. While most pesticides listed under the Stockholm Convention on Persistent Organic Pollutants [14] eventually degrade in the environment, some are highly persistent and capable of long-range dispersion. In certain cases, water contamination can persist for many years--even decades--after the pesticide has been eliminated from use. Groundwater, which serves as a vital source of drinking water in rural areas and is also used to irrigate agricultural land, is particularly vulnerable. As a result, monitoring groundwater quality is essential for effective environmental risk assessment (ERA) [15]. The International Agency for Research on Cancer (IARC) has classified several pesticides as carcinogenic agents [16]. Risk assessment is described as the probability of any adverse effect on human health occurring within a certain time frame [17; 18].