Lead and copper release from full and partially replaced harvested lead service lines: Impact of stagnation time prior to sampling and water quality.

Partial lead service line replacement (PLSLR) results in the addition of a new galvanic connection and can increase lead concentrations at the tap. Focus has been given to minimizing lead release after PLSLR, but little information is available on the impact of lead remedial actions on copper concentrations, especially before passivation occurs. The impact of water quality (decreased chloride-to-sulfate mass ratio from 0.

Study of the long-term impacts of treatments on lead release from full and partially replaced harvested lead service lines.

Long-term (155 weeks) Pb concentrations, following partial lead service lines replacements (PLSLR), were measured in a flow through pilot made of harvested lead service lines (LSL) from the distribution system of the City of Montreal. The present study also investigates how release of Pb from full and partial LSLs is influenced by: pipe diameter, decrease in chloride-to-sulfate mass ratio (CSMR) from 0.9 to 0.

Sampling in schools and large institutional buildings: Implications for regulations, exposure and management of lead and copper.

Legacy lead and copper components are ubiquitous in plumbing of large buildings including schools that serve children most vulnerable to lead exposure. Lead and copper samples must be collected after varying stagnation times and interpreted in reference to different thresholds. A total of 130 outlets (fountains, bathroom and kitchen taps) were sampled for dissolved and particulate lead as well as copper.

Short- and Long-Term Lead Release after Partial Lead Service Line Replacements in a Metropolitan Water Distribution System.

Thirty-three households were monitored in a full-scale water distribution system, to investigate the impact of recent (<2 yr) or old partial lead service line replacements (PLSLRs). Total and particulate lead concentrations were measured using repeat sampling over a period of 1-20 months. Point-of-entry filters were installed to capture sporadic release of particulate lead from the lead service lines (LSLs).

Evaluation of exposure to lead from drinking water in large buildings.

Lead results from 78,971 water samples collected in four Canadian provinces from elementary schools, daycares, and other large buildings using regulatory and investigative sampling protocols were analyzed to provide lead concentration distributions. Maximum concentrations reached 13,200 and 3890 μg/L following long and short stagnation periods respectively. High lead levels were persistent in some large buildings, reflected by high median values considering all taps, or specific to a few taps in the building.

Application of lead monitoring results to predict 0-7 year old children's exposure at the tap.

Dwellings with/without a lead service line [LSL] were sampled for lead in tap water in Montreal, during different seasons. Short-term simulations using these results and the batchrun mode of the Integrated Exposure Uptake Biokinetic (IEUBK) model showed that children's exposure to lead at the tap in the presence of an LSL varies seasonally, and according to the type of dwelling. From July to March, for single-family homes, the estimated geometric mean [GM] blood lead level [BLL] decreased from 2.

The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1-5 years in Montréal (Québec, Canada).

Lead is neurotoxic at very low dose and there is a need to better characterize the impact of domestic sources of lead on the biological exposure of young children. A cross-sectional survey evaluated the contribution of drinking water, house dust and paint to blood lead levels (BLLs) of young children living in old boroughs of Montréal (Canada). Three hundred and six children aged 1 to 5 years and currently drinking tap water participated in the study.

Impact of treatment on Pb release from full and partially replaced harvested Lead Service Lines (LSLs).

Release of lead from 80% partially replaced service lines was compared to full lead service lines using harvested-stabilized lead pipes and field brass connectors. After more than a year of stabilization, lead release was consistent with field samples. Over the relatively short duration partial replacement of lead pipe by copper pipe (3 months), generated high lead release, attributed to galvanic corrosion, resulting in a final outcome for lead release that was even worse than for a full lead pipe.

Impact of water treatment on the contribution of faucets to dissolved and particulate lead release at the tap.

A field study was performed in a building complex to investigate the extent and sources of lead (Pb) release in tap water and brass material was found to be the main contributor in the very first draw (250 mL). Based on these results, a pilot installation was built to study Pb leaching from old and new faucets in the presence and absence of a connection to Cu piping. Four water quality conditions were tested: i) no treatment; ii) addition of 0.

Source and occurrence of particulate lead in tap water.

Lead samples were collected at the tap from homes with lead service lines (LSLs) in a full-scale utility using both random daytime (RDT) and particulate stimulation sampling (PSS) protocols. Analysis of the results revealed two sources and occurrences of particulate lead. A first source is due to corrosion of lead-bearing elements in the premise plumbing (PP) and occurs mostly at low to moderate concentrations < 3 microg/L, with some sporadic higher concentrations (4-12 microg/L).

Kinetic and thermodynamic aspects of adsorption of arsenic onto granular ferric hydroxide (GFH).

Relatively limited information is available regarding the impacts of temperature on the adsorption kinetics and equilibrium capacities of granular ferric hydroxide (GFH) for arsenic (V) and arsenic (III) in an aqueous solution. In general, very little information is available on the kinetics and thermodynamic aspects of adsorption of arsenic compounds onto other iron oxide-based adsorbents as well. In order to gain an understanding of the adsorption process kinetics, a detailed study was conducted in a controlled batch system.