The author has prepared a mathematical model capable of predicting concentrations of lead in the atmosphere and in soil near a highway arising from a form of transport. The model is formulated in a set of linear, first-order, ordinary differential equations with variable transfer coefficients. A second order runge-kutta numerical integration scheme is applied to obtain results. Input consists of initial conditions, physical system characteristics, meteorological parameters, and source characteristics. Results obtained from the model indicate that about 56 percent of the total lead consumed is deposited in soil within one hundred metres of a highway. Approximately 22 percent goes off in longer range transport. Based on a comparison with limited field data, the model over-predicts concentrations of lead in soil by about 20 percent. Less than 0.5 percent of the lead is transported from upper layers into deeper soil. At five metres from the edge of the roadway, the model predicts typical accumulation rates of about 50-90 micrograms of lead per gram of soil per year. At 55 metres from the highway, typical accumulation rates in soil are approximately 5 to 7 percent of those at five metres. An estimate of atmospheric and soil lead levels ten years hence was made. The model is especially well suited to provide information about effects of alternative control measures or changes in lead use patterns. /TRRL/

  • Corporate Authors:

    University Microfilms Limited

    High Wycombe,   England 
  • Authors:
    • Watkins, D R
  • Publication Date: 1974-8


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 187 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00133945
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: Thesis
  • Files: ITRD, TRIS
  • Created Date: Nov 9 1977 12:00AM