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Access to safe water supply--a major determinant of public health--is less than 50% in Madagascar, and access to piped, treated water remains out of reach financially for many in the urban and peri-urban areas where available. The Self-supply option of the Pitcher Pump has been meeting the need for household water in coastal areas of Madagascar since the early 1960s and has proven a sustainable option for many. These pumps make use of leaded components in the construction, however, which may pose a health risk for heavy metal intoxication and therefore cause the water to be unsafe for drinking and cooking. This study assesses the potential for lead (Pb) leaching from Pitcher Pump systems into water at levels of health concern. The objectives of this study are to assess Pb concentrations in water drawn from Pitcher Pumps, to determine the relationship between various factors and the Pb levels, to make a preliminary assessment of public health implications of Pb contamination, and to offer informed recommendations to reduce the likelihood of consuming contaminated water. A field study was undertaken to measure concentrations of dissolved Pb in water from Pitcher Pumps under recently flushed and first-draw pumping conditions at 18 households in the city of Tamatave, Madagascar. Variables potentially affecting Pb leaching were determined including pump age, depth to the well screen, pump manufacturer, season of sample collection, and basic water quality indicators. Sampling campaigns were conducted three times over the course of eight months. Time-release case studies were also carried out at two households to determine the time scale over which the Pb concentration in stationary water reaches equilibrium with the Pb-containing system components. Pilot studies of iron (Fe)-for-Pb substitution of select pump system components were carried out at the same two households to attribute the major contribution of Pb leaching to one set of parts and to assess one strategy for decreasing dissolved Pb concentrations. Finally, the Internal Exposure Uptake Biokinetic Model for Lead in Children (IEUBK Model) of the US Environmental Protection Agency (EPA) was employed to estimate realistic blood lead levels (BLLs) in children under five years of age, based on Pb concentrations measured in the water. Of the 18 pumps sampled, 15 produced at least one sample exceeding the World Health Organization (WHO) provisional guideline of 10 [um]g/L dissolved Pb in water. Specifically, 67% of all samples showed concentrations above 10 [um]g/L under first-draw pumping conditions. Flushing the pumps prior to use decreased the Pb levels significantly (p < 0.0001), with only 35% of samples exceeding the provisional guideline. Under flushed conditions, the median Pb concentration in pumped water was 9 [um]g/L, down from 13 [um]g/L at one hour of inactivity. No statistically significant correlations were observed between measured Pb concentrations and factors like the season of sample collection, pump age, manufacturer, or water quality indicators like pH or temperature. Under first-draw conditions, the concentration of Pb in water increased with increasing duration of pump inactivity, until equilibrium was reached with the leaded pump components. For two pumps, substitution of Fe valves for Pb greatly decreased Pb concentrations in the water, from 37-100 [um]g/L and 7-24 [um]g/L down to 3-4 [um]g/L and 2-8 [um]g/L, respectively. Model-predicted geometric mean BLLs in children range from about 2-8 [um]g/dL, in some instances exceeding the Centers for Disease Control and Prevention (CDC) guideline for an elevated BLL (5 [um]g/dL), depending on the exposure concentrations. This study finds that water provided by Pitcher Pump systems in Madagascar frequently exceeds the WHO provisional guideline value for safe consumption under first-draw conditions, and may do so even after flushing the pumps. The Pb concentrations measured in the field have the potential to elevate BLLs in children under five to levels implicated in serious health issues. Leaching of Pb into the water is therefore an issue of concern for users of the Pitcher Pump systems in Tamatave, and likely for other areas served by this technology. Flushing the pumps before water collection generally reduces Pb levels in the water. These results suggest that most of the Pb leaches from pure Pb check valve weights at the mouth of the pump, and consequently, a substitution of Fe weights on the valves greatly reduces Pb concentrations and the probability for exceeding the WHO provisional guideline. Relatively simple operational changes on the part of the pump manufacturers and the pump users might, therefore, help to ensure the continued sustainability of Pitcher Pumps in eastern Madagascar.

Sediments rich in sulfide were deposited in the Littorina sea in an environment that was shallow, anoxic,and reductive. The sediments were brought above sea level by isostatic uplift and can now be foundalong the coast of the Baltic sea. These sulfide rich sediments oxidize when they are exposed to air whenthe water table is lowered due to uplift, anthropogenic activities, or hydrological droughts. Oxidation ofsulfate soils will lower the pH and mobilize metals in the soil that will leach into adjacent rivers and willimpact the water chemistry and damage ecosystems. A few studies have noted that leaching increasesin sulfate soils after drought which has resulted in fish death. The impact of droughts on leaching from sulfate soils were investigated in nine rivers (Flarkbäcken,Hertsångerälven, Kvismare canal, Kyro river, Närpes River, Persöfjärden, Storbäcken, Tjuståsaån, andToby river) by looking at time series of sulfate concentrations and drought periods. The impact on riversafter a drought was studied by plotting the deviation from median specific discharge in summer andautumn against the deviation from median concentration of SO42-, a suite of metals and pH the followingseason with high discharge e.g. spring. The metals that were examined in the river were Aluminum (Al),Cadmium, (Cd), Cobalt (Co), Cupper (Cu), Iron (Fe), Manganese (Mn), Nickle (Ni), Zinc (Zn).TheKendall’s τ was then used to determine if the relationship between discharge and leached compoundconcentration was significant and which direction it had. In the sulfate timeseries the hydrological droughts generally coincided with low SO42- and werefollowed by SO42- peaks. The sulfate concentrations increased significantly after droughts, and theincrease in SO42- lasted for 1-3 years for most rivers. In two Finnish rivers the SO42- remained higher alonger time of 5 years in Kyro river and Närpes river after multiyear droughts. In Kvismare canal, Kyroriver, Närpes river and Tjuståsaån the SO42- concentration was higher in the mid-1900s which could bedue to changes in ditching activity, the acid sulfate soils transitioning to post active sulfate soils afterthe ditching activity stopped in the regions, or SO42- air deposition historically being greater. SO42-, Co, Ni, and Zn had negative significant correlations in a majority of the rivers, while pH, Fe,and total organic carbon had significant positive correlations a majority of rivers. A negative correlationindicates high concentrations of the leached compound after a drought while positive correlationsindicate low concentrations of the leached compound after a drought. Al, Cd, Cu, and Mn did not havea significant correlation in a majority of the rivers which could be due to their dependence on pH whichwill not always change in the rivers in spring due to acidic water leaching from acid sulfate soils sincethe acidic water will be diluted by meltwater. / Efter senaste istiden var vattnet i havet syrefritt och reducerande vid havsbotten, vilket ledde till attsulfidmineral avsattes. Dessa sulfidrika sediment har hamnat ovanför havsytan på grund avlandhöjningen och finns i kustnära områden runt östersjön. Sulfidsedimenten oxiderar om de kommer ikontakt med syre vilket kan ske på grund av landhöjning, mänskliga aktiviteter, eller torka som sänkergrundvattennivåerna. När sulfatjordarna oxiderar sänks pH i jorden och metaller frigörs vilka sedanlakas ur jorden och påverkar närliggande vattendrag och ekosystem. Lakning av metaller har i någrastudier setts öka efter extrem torka vilket i vissa fall har lett till fiskdöd. I nio vattendrag (Flarkbäcken, Hertsångerälven, Kvismare kanal, Kyro älv, Närpes å, Persöfjärden,Storbäcken Tjuståsaån och Toby å) undersöktes hur torka påverkar urlakning från sura sulfatjordar. Deämnen som undersöktes var Aluminium (Al), Kadmium (Cd), Kobolt (Co), koppar (Cu), Järn (Fe),Mangan (Mn), Nickel, (Ni), Totalt Organiskt Kol (TOC), och Zink (Zn). Sambandet mellanvattenföringens avvikelse från medianen under de sommar samt höst och avvikelsen avkoncentrationerna av urlakade ämnen från medianen följande årstid med högt flöde plottades för attundersöka hur sambandet såg ut. De statistiska testerna Kendalls τ användes för att utvärdera om enkorrelation existerade och i vilken riktning den gick. Sulfatkoncentrationerna var generellt sett väldigt låga under torrperioder men ökad snabbt efter atttorkan avtagit. Den förhöjda sulfatkoncentrationen varade generellt sett i 1-3 år för de flesta vattendrag.Det fanns däremot två undantagsfall då sulfatkoncentrationerna var förhöjda i Kyro älv och Närpes åunder 5 år efter en torrperiod som varat i flera år. I Kvismare kanal och Tjuståsaån varsulfatkoncentrationerna, högre under mitten av 1900-talet. De högre koncentrationerna av sulfat kanbero på att det var mer dikning, eller större mängd luftföroreningar under denna period. Sambanden för sulfat, Co, Ni och Zn visade att efter torra perioder var koncentrationerna högre i enmajoritet av vattendrag än normalt. pH, Fe och TOC visade på ett motsatt samband. Efter torrperiodersjönk därmed koncentrationen Fe och TOC i en majoritet av vattendragen. Al, Cd Cu, och Mn hadesignifikanta samband i mindre än 50 % av vattendragen vilket kan vara till följd av att de är beroendeav pH som själv inte hade en tydlig korrelation i alla vattendrag. pH sjunker i många fall inte särskiltmycket till följd av en torka då vattnet som lakas ut från sulfatjorden späds ut av smältvatten undervåren.