Background: TSM is one of the most tragic lead sites in the world. The severity of lead exposures are unprecedented in recent history with mean blood lead levels in area children in excess of 100 µg/dl and individual readings > 350 µg/dl. According to Senegalese health authorities, 18 children died as a direct result of this epidemic in 2007-08. TSM has been the scene of Used Lead Acid Battery (ULAB) recovery since the 1970's. Multiple groups of local individuals recovered lead from batteries to manufacture weights for local fishermen. Several thousand tons of discarded battery sludge accumulated in the area over the past three decades. In 2007, dramatic increases in lead prices stimulated East Indian traders to purchase the lead oxide sludge. However, to minimize shipping costs, about 200 local women were employed to "sift" out beach sand that had accumulated with the sludge. The process involved transporting, spreading, drying, collecting, sifting and bagging the lead dust. Bags of product lead were stored in the women's homes, prior to sale. Many women brought their infants and toddlers with them to the sifting operation.

TG International Initiative Activities: Limited emergency remediation activities were undertaken in April and May of 2008. Nearly 300 tons of the lead product was confiscated from local homes. The WHO tested family members of the deceased children and forty-one children were hospitalized and placed in foster care. However, massive flooding of the area during the rainy season delayed further action. After the flood subsided, TerraGraphics and the Blacksmith Institute conducted extensive sampling and interviews of TSM population; and a health response and remediation strategy was developed and adopted in April 2009.

The strategy included establishment of sentinel homes in the community where intensive interviews an sampling were conducted to determine the extent and severity of continuing exposures and identify active lead health pathways. These homes and resident children are being monitored to assess the effectiveness of the cleanup.

Blood Lead Testing: TerraGraphics and the Blacksmith Institute assisted the Senegalese Ministry of Health in developing and implementing a blood lead monitoring and follow-up protocol and provided testing equipment. A total of 97 individuals from 10 homes including 68 children and 29 mothers were tested in March 2009, one year following the epidemic. Thirty children, or 57% of all children less than 10 years of age, had blood lead levels exceeding 70 µg/dl. Of 19 children age 18 months to 4 years, 15 had blood lead levels >70 µg/dl. The estimated total population similarly affected ranges from 250 to 1500 children.

Soil Contamination Levels: Soil concentrations were extremely high throughout the community, usually being reported in percent lead. The final cleanup plan estimates more than 4000 m³ of waste >10% lead, 3000 m³ of 1-10% Pb and 1300 m³ of .1-1% Pb soils requiring excavation.

Home Interior Contamination: Severe house dust lead loadings were observed within homes and buildings. Average floor lead loadings were 44,000 µg/m², exceeding the U.S. cleanup criteria by a factor of 100. Interior home house dust lead levels ranged as high as 27,000 mg/kg by concentration and 379,000 µg/m² by lead loading.

Remedial Activities: The cleanup is being funded by GreenCross of Switzerland, the Blacksmith Institute and TerraGraphics. The first phase of the cleanup commenced in June 2009 and will be completed in 2010. More than 1100 cubic meters of the most contaminated soils was removed from residential lots and streets and disposed of in the Dakar municipal landfill. About half of this waste was classified as Principal Threat Material (PTM >10% lead) and the remainder ranged from 1-10% lead. Exterior mean soil concentrations were reduced from >10,000 mg/kg to < 2500 mg/kg in Phase I. All soils exceeding 1000 mg/kg should be removed by July 2010. Interior cleaning commenced following the initial soil removal. TerraGraphics and Senegalese Ministry of Environment personnel developed a wet/dry HEPA vacuum protocol consistent with local cultural practices and trained and equipped two crews of TSM residents who decontaminated fifty buildings, housing several hundred families over the next few months. Preliminary data indicate that 70% to 90% removal was achieved, but some recontamination was noted in the subsequent rainy season.

In total, more than fifty local workers were hired and employed for three weeks in the soil removal. Two teams of six local villagers were trained to conduct the interior decontamination and were employed for five months for the initial cleaning. Wages were $5 to $10 per day, and were greatly appreciated, as people live on $2-3 per day, as unemployment since the battery smelting operations were stopped exceeds 80%. Some of the mothers on our cleanup crews lost children in last year’s epidemic. The crews take their work seriously and do an effective job with considerable good will.

In May/August of 2010, an additional 4000 m³ of soil will be removed and replaced with clean soil. A second round of interior sampling and cleaning will follow elimination of the soil source. Two rounds of cleaning should affect an overall 90%+ reduction in interior exposures. A third round of blood lead testing is scheduled for April 2010.

• MSNBC
• The World
• Blacksmith Institute
• PDF Report on TSM
• TSM Poster