Exposure to trihalomethanes and cancer risk: a novel quantitative analysis considering water consumption habits | Exposición a trihalometanos y riesgo de cáncer: un análisis cuantitativo considerando los hábitos de consumo del agua

Long-term exposure to disinfection byproducts (DBPs) has been associated with various adverse health effects, including an increased risk of cancer. In order to assess the risk of cancer due to exposure to trihalomethanes (THM), 464 water samples were taken at different monitoring points in 15 representative municipalities of Boyacá, Colombia. Gas chromatography was used to measure the concentration of THM in the water. To determine the consumption habits of the exposed population, a total of 3016 surveys were conducted. Distributions representing the variables involved in risk calculation were identified using the RStudio® program. Risk was calculated through Monte Carlo simulations using the Crystal Ball® program, employing USEPA equations with modifications to accommodate consumption habits. The most relevant concentrations were measured for chloroform (CF) and bromodichloromethane (BDCM) in the total trihalomethanes (TTHM). Although a large percentage of concentrations were found to be below the detection limit (LD), maximum concentrations of 180 μgL-1 for CF and 20 μgL-1 for BDCM were identified. Average risks were within the ranges of 2.40×10-6 – 1.65×10-5 (ingestion), 1.57 ×10-6 – 2.15×10-5 (inhalation), and 2.68×10-6 – 2.54×10-5 (dermal absorption). In general, the average risks from exposure through all three pathways were within the low-priority zone (10-5<CR<10-4), with some maximum values falling within the high-priority zone (CR>10-4). Sensitivity analysis showed a significant impact of exposure factors, Dermal Exposure Rate and the variables Ft (frequency multiplied by event exposure time) and Ct (liquid/gas transfer factor) on oral, dermal and inhalation risk calculations, respectively. This highlights the need for control over specific habits such as the use of gloves, proper use and maintenance of in-home treatment systems (HTS), among others, and THM concentrations to reduce the risk of potential adverse health effects.

Ministerio de ciencia, tecnología e innovación a través del proyecto No. 84746

Magíster en Ingeniería Ambiental

Maestría