Degradation of asbestos – Reinforced water supply cement pipes after a long-term operation

A critical review of asbestos concentrations in water and air, according to exposure sources

“…According to Zavasnik et al (2022) [ 30 ] the drinking water supply system in the main world powers mostly is of asbestos-cement pipes. These researchers carried out the analysis of asbestos samples from the degradation of asbestos-cement pipes in the city of Ljubljana, Slovenia, with approximately 6 decades of operation.…”

“…However, fiber ingestion is also considered a likely route, although the adverse effects are less clear, and it is still a matter of discussion in the scientific community. According to Zavasnik et al (2022) [ 30 ], some studies point to the causal effect of ingested asbestos on gastric and colorectal cancer, but the WHO has defined that there is no conclusive evidence that ingested asbestos is carcinogenic using a series of extensive investigations as evidence, [ 31 ]. Zheng et al (2019) [ 32 ], focused on trying to improve understanding of the damage caused by ingested asbestos in drinking water by qualitatively and quantitatively analyzing six types of asbestos from groundwater and drinking water using FT-IR (Fourier transform infrared spectroscopy) and tracking the Asbestos migration in animals “live”.…”

“… Soil Italy 1.1–0.01 (%p/p) [ 19 ] Holland 1.1–0.01 (%p/p) Australia (West) 0.05–0.001 (%p/p) United States Based on site-specific risk assessment Air/Occupational Exposure World Health Organization 0,001–0,0001 f/cm 3 [ 15 ] Occupational Safety and Health Administration (OSHA) 0.1 fibras/cm 3, TWA 8h [ 45 , 46 ] National Institute for Occupational Safety and Health (NIOSH) 0.1 fibras/cm 3, TWA 10h [ 5 ] American Conference of Governmental Industrial Hygienists (ACGIH) 0.1 fibras/cm 3, TWA 8h [ 47 ] Water United States Environmental Protection Agency (US EPA) 7 million fibers/liter (MFL) (fibers longer than 10 μm). [ 30 , 48 ] World Health Organization There is no consistent evidence that ingested asbestos is dangerous to health [ 31 , 49 ] %w/w: percentage weight on weight. TWA: Time-Weighted Average” (TWA), 8-h weighted average concentration not to be exceeded in any 8-h shift for 40-h workweeks.…”

The concentration and prevalence of asbestos fibres in Christchurch, New Zealand's drinking water supply

“…The outer skin of the pipe is also vulnerable to decay especially in conditions of high groundwater tables where sulfate attack may occur in acidic and low iron environments (Hu et al 2013). Moreover, the degradation of asbestos cement pipes is chemically complex, and cannot be discerned from age alone (Zavanšnik et al 2021). Chlorination of water, for example, can exacerbate the potential for pipe corrosion, but conditions conducive to scaling can be protective, so the only effective method for determining the potential rate of asbestos fibre release into the piped network is via direct pipe inspection (Zavanšnik et al 2021).…”

“…Moreover, the degradation of asbestos cement pipes is chemically complex, and cannot be discerned from age alone (Zavanšnik et al 2021). Chlorination of water, for example, can exacerbate the potential for pipe corrosion, but conditions conducive to scaling can be protective, so the only effective method for determining the potential rate of asbestos fibre release into the piped network is via direct pipe inspection (Zavanšnik et al 2021). Thus, a confluence of conditions cause asbestos pipe deteriorationthe age of the pipe, the manufacturing standards of the time and manufacturing defects, the chemical corrosivity from conveying soft water, fluctuating groundwater tables in acidic soil conditions, or the propensity for pipe bending through ground movement (either from poor installation, seasonal disturbance, or ground motion).…”