Resources

Guide to Soil

How to Use This Module

Glossary

Video Clip

Situation for Activities

Geographic Information System

Lead Swab Lab

Lead Extraction Lab

Creative Writing: Malade Papillion

Critical Reading

Stakeholder Debate

Sunshine State Standards

Related Links

Bibliography

Soil Module: Geographic Information System
Purpose
To use actual Miami-Dade County spatial data to learn basic principals of geographic information Systems (GIS) and to explore the concept of environmental health, specifically in regard to geographic analysis and hypothesis development.

Overview
After a brief introduction to GIS and its uses, actual Miami-Dade County maps are introduced and students are asked questions pertaining to the map themes. Students are asked to make predictions before viewing the actual lead poisoning cases by location.

Time Required
one two-hour class period

Key Concepts
As a result of industrialization, lead is everywhere in our environment.
Lead is a major problem, particularly for inner city children.
Lead has a number of pathways into the human body.
Sources of lead exposure vary according to geographic elements and risk factors.
Analysis of data using various thematic maps can help us predict the source of lead exposure in individuals or population clusters.

Skills
understanding GIS and its value as a public health tool
interpreting spatial data
making predictions based on GIS data and developing hypotheses

Materials
overhead projector
transparencies
copying machine for transparencies

Background
Geographic Information Systems (GIS) are computer-based software used to create, view, and analyze geographic databases. Geographic Information Systems link data and geography digitally in order to make maps. This technology provides a useful way to display spatial and temporal relationships among data.

Researchers, public health professionals, policy makers, and others use GIS to better understand geographic relationships that affect health outcomes, public health risks, disease transmission, access to health care, and other public health concerns. Geographic Information Systems are being used with greater frequency to address neighborhood, local, state, national, and international public health issues.

Procedure
Students can work as individuals or in groups. They will be provided with a hard copy version of the exercise to view maps and answer questions. Teachers can make transparencies to guide the class through the module and ultimately overlay the maps to simulate a GIS experience.

Geographic Lead Patterns
Much of our landscape, especially in inner city areas, is contaminated with lead. Lead can be found in paint and dust in homes. There is also lead-contaminated soil in yards and playgrounds. Lead in children's bodies and bones.

Such is the legacy after a century of adding tens of thousands of tons of the heavy metal to paint, gasoline and other everyday products. Today, old paint, dust and soil, drinking water, and health care supplies are the major sources of lead exposure. Warnings about lead paint abound. Lesser known--and possibly more important--is the threat from lead-contaminated soil and dust in urban homes and yards.

Not all areas bear the same contamination. Soil lead content varies between and within cities because of historical traffic congestion, size and age of the city, type and amount of industry present, and the type of soil. Of these, traffic--and the associated use of leaded gasoline--plays the most important role in determining where lead is found in soil. In general, city size, an area's location relative to the urban center, and the soil's location relative to buildings and the street determine soil lead content.

QUESTIONS
Using the maps below as needed, answer the following questions:

1. What kinds of information or databases can a GIS utilize?
2. List the major roads on the Miami-Dade Major Roads, Highways, and Zipcode Blocks map.
3. How many vehicles do you think travel on this county road system? How would you find out?
4. Besides automobile emissions, what are other sources of lead from transportation?
5. Identify a neighborhood or road on the Miami-Dade Superfund Site Locations and Zipcodes map that has a high concentration of waste sites.
6. What types of businesses in Miami-Dade County generate hazardous waste? Where can you find this information? (DERM)
7. How can hazardous waste sites cause lead poisoning in children?
8. Identify the neighborhoods of older housing on the map of Miami-Dade pre-1950 Housing.
9. What are some other ways to classify housing?
10. When was your house built?
11. Identify neighborhoods with lower socioeconomic status on the Percent of Miami-Dade Households with Poverty Status by Zipcode map.
12. Explain how lead poisoning can be associated with both high and low socioeconomic statuses.
13. Identify the Miami River on the Miami-Dade Rivers, Canals, Lakes, and Zipcode Blocks map. How could one find out if the Miami River is safe to swim in? Fish from?
14. Are there any areas with a high concentration of canals? Are these natural waterways?
15. What do you think is the most important predictor of lead poisoning? Why?
    a. Based on your prediction, indicate on the blank map the areas where you expect to find the most lead cases.
    b. Do any other predictors change your expectations? Why or why not?
16. What other information would you want to incorporate into your map analysis to predict where lead cases would occur? a. Why? b. Where would you look for it?
17. Examine the Lead Poisoning Cases in Miami-Dade County in 1999 map. Identify the neighborhoods with apparently large numbers of lead poisoning cases.
18. Superimpose all maps and interpret the relationship between possible routes of exposure and lead cases. Was your prediction correct? Why or why not?
19. Are there any other geographic predictors you would like to analyze now to further explain the distribution of lead poisoning cases?

Further Investigation
There are many websites and other resources with geographic-based data that could be used in this mapping exercise. Possible GIS resources include:

EPA Office of Pollution Prevention and Toxins

Centers for Disease Control and prevention: Lead Poisoning Prevention Center

US Census Bureau

U.S. Department of Housing and Urban Development

Assessment
Assign the following mapping components to each student team as a guide to their work:

interpret the maps to answer the questions
answer each question using the maps and data provided to you
illustrate the questions on the maps provided to you
formulate hypotheses or predictors for the lead case maps
if applicable, each group member should be the principle investigator on at least one question

Allocate points for the following components of the Team Presentation:

Were the students able to answer all the questions in both written and map form?
Was the student able to answer questions about the facts and their conclusions while defending their point of view?
Was the appropriate scientific terminology used?
Did the students cite their sources?
If applicable, was each group member actively involved in the mapping exercise?

Answer Key

1. What kinds of information or databases can a GIS utilize?
   Zoning districts, school districts, taxing districts, road-building plans, census data, voting precincts, property boundaries, and locations of abandoned fuel tanks.
   
2. List the major roads on the Miami-Dade Major Roads, Highways, and Zipcode Blocks map.
   US-1, I-95, I-75, SR-826, SR-874, SR-821, SR-836, SR-27 (Okeechobee Road), 177th Ave (Krome Avenue), SW 8th Street (Tamiami Trail, US-41), etc.
   
3. How many vehicles do you think travel on this county road system? How would you find out?
   
   

   Miam-Dade County Commuters	Total
   Licensed Drivers	1,597,975
   Workers 16 years and over	887,996
   Drive alone	642,669
   Carpool	138,328
   Use public transportation	52,162
   Use other means	14,292
   Walk or work at home	40,545

   
   Sources of this information include: Florida Department of Transportation, the US Census: American Fact Finder, and the Miami-Dade County website.

4. Besides automobile emissions, what are other sources of lead from transportation?
   Lead paint can be found on bridges and steel structures. It is also transported on highways.

5. Identify a neighborhood or road on the Miami-Dade Superfund Site Locations and Zipcodes map that has a high concentration of waste sites.
   
   Okeechobee Road along the Miami River is an industrial area that has a high concentration of waste sites; also Medley.

6. What types of businesses in Miami-Dade County generate hazardous waste? Where can you find this information? (DERM)
   Many types of businesses generate hazardous waste. Some are small companies that may be located in your community. For example, dry cleaners, auto repair shops, gun ranges, hospitals, exterminators, and photo-processing centers typically generate hazardous waste. Some hazardous waste generators are larger companies like chemical manufacturers, electroplating companies, battery recycling plants, lead smelting facilities, and petroleum refineries.

7. How can hazardous waste sites cause lead poisoning in children?
   Dust or soil, run-off or groundwater contamination, para-occupational pathways, and the food chain are ways that hazardous waste sites can cause lead poisoning in children.

8. Identify the neighborhoods of older housing on the map of Miami-Dade pre-1950 Housing.
   Coral Gables, Miami Springs, Miami Beach, or neighborhoods near I-95

9. What are some other ways to classify housing?
   Household size, household type (e.g. single family, apartment, condominium, etc.), mortgage status, value of house, amount of rent, age of tenants, race of tenants, etc. are all ways to classify housing.

10. When was your house built?
    
11. Identify neighborhoods with lower socioeconomic status on the Percent of Miami-Dade Households with Poverty Status by Zipcode map.
    

12. Explain how lead poisoning can be associated with both high and low socioeconomic statuses.
    High or low socioeconomic status: Both rich and poor people live in older homes, many of which still have lead-based paints. Data show that the risk of high blood lead levels for all low income children living in pre-1946 housing is great (16.4%); African-American children living in this type of housing are at an alarmingly higher risk (21.9%) of having elevated blood lead levels. (NLHIC 2000)
    
    Low socioeconomic status: There tend to be more hazardous waste sites in low-income communities than in high-income communities.

13. Identify the Miami River on the Miami-Dade Rivers, Canals, Lakes, and Zipcode Blocks map. How could one find out if the Miami River is safe to swim in? Fish from?
    The Department of Environmental Resource Management of Miami Dade County (305-372-6529) or the Miami-Dade County Health Department (305-324-2400) will be able to provide this information.

14. Are there any areas with a high concentration of canals? Are these natural waterways?
    East of Homestead, near downtown (Miami River), is an area with a high concentration of canals. These canals are not natural waterways. They were human-made for commerce. Natural waterways usually meander and are not so straight.

15. What do you think is the most important predictor of lead poisoning? Why?
    a. Based on your prediction, indicate on the blank map the areas where you expect to find the most lead cases.
    b. Do any other predictors change your expectations? Why or why not?
    
    The age of a house could be a good predictor of whether or not its paint contains lead. The presence of a major road may indicate the deposition of lead in the soil from vehicles, paint on highway structures, etc. Hazardous waste sites are probably NOT the best way to predict the occurrence of lead poisoning.

16. What other information would you want to incorporate into your map analysis to predict where lead cases would occur?
    a. Why?
    b. Where would you look for it?
    
    You could look for immigration patterns since immigrants from areas both inside and outside the United States may have had greater exposure to lead. You could also incorporate any existing monitoring sites for lead in houses or soil.

17. Examine the Lead Poisoning Cases in Miami-Dade County in 1999 map. Identify the neighborhoods with apparently large numbers of lead poisoning cases.
    Miami, Homestead, Coral Gables appear to have large numbers of lead poisoning cases.

18. Superimpose all maps and interpret the relationship between possible routes of exposure and lead cases. Was your prediction correct? Why or why not?
    Housing age and major roads do appear to be the most likely routes of exposure to lead.

19. Are there any other geographic predictors you would like to analyze now to further explain the distribution of lead poisoning cases?
    You could look for immigration patterns since immigrants from areas both inside and outside the United States may have had greater exposure to lead. You could also incorporate any existing monitoring sites for lead in houses or soil.

Thanks to the EPA (Environmental Protection Agency) The Comprehensive Environmental Response, Compensation, and Liability Act (also called the Superfund) provides billions of dollars for cleaning up abandoned waste dumps.

Quick Fact: It is estimated that three-quarters of the nation's houses built before 1978 have at least some lead-based paint, with those homes built before the 1950s likely to have high amounts.