EPA/742B98008
CIS, Pollution Prevention,
and Public Health
Local health officials are continually searching for new and improved tools that will
help to assess local hazards and identify opportunities to protect community
health through prevention strategies. Geographic information systems (GIS) are pow-
erful tools that enhance a health department's ability to protect the community. Using
examples of preventing pollution and reducing risk of exposure to communities, this
guide answers basic interest and start-up questions, addresses benefits and limitations,
and illustrates the value of GIS for local health departments.
f
This guide is one of three parts of NACCHO's pollution prevention activities in 1998.
Other activities include:
*»• the development of a companion document entitled GIS Pollution Prevention Case
Studies that provides three examples from local health departments of the potential
uses of geographic information systems resulting in integration of pollution preven-
tion practices into local health programs; and
^ the development of an introductory GIS session at the 1998 NACCHO Annual
Conference.
What are GIS?
GIS are computer-based tools used to present multiple types of data on a map from a
database in which each record has geographic reference (i.e., latitude and longitude).
Maps are not only created to display data, but also to emphasize their spatial patterns
and relationships and associated health, demographic, environmental, and geographic
characteristics. In addition to displaying data pictorially, GIS applications have func-
tions that standard databases do not, such as creating routing by time and distance,
tracking the spread of an event, and identifying residents of an affected area. GIS also
provide many functions that the public can use every day utilizing only database
features (e.g., users can simply
enter an address or zip code
and be told any number of
features about that area). GIS
provides increased access to
information and the opportu-
nity to analyze complex data,
solve problems, and present
data in a graphical format that
decision makers and the public
can easily see and understand.
INSIDE
GIS, Pollution Prevention, and Pubic Health 2
Issues GIS can address —...........— 2
How it Works: System Design. 4
Types of Applications......—....... 5
Sharing Resources Among Agencies 6
Available Resources......... 7
The Nuts and Bolts: Hardware Requirements 11
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National Association of County & City Health Officials
What is Pollution Prevention?
Pollution Prevention is defined in the Pollution
Prevention Act of 1990 as any practice which
1) reduces the amount of any hazardous sub-
stance, pollutant, or contaminant entering any
waste stream, or otherwise released into the
environment (including fugitive emissions)
prior to recycling, treatment, or disposal; and 2)
reduces the hazards to public health and the
environment associated with the release of such
substances, pollutants, or contaminants. Pollu-
tion prevention practices encourage increased
revenue to industry though reduction in liability
and hazardous material handling costs, de-
creased risk to workers and the public, increased
worker productivity, better product and com-
pany image, and cost cutting through quality
management of the manufacturing process.
Pollution Prevention
and Public Health
Pollution prevention brings environmental
protection together with disease prevention.
When we prevent environmental problems from
occurring, we protect human health in a variety
of ways. For example, by reducing or eliminat-
ing the use of hazardous substances from indus-
trial processes, we can prevent those substances
from entering the air, water, soil, and food chain.
And, by finding alternative and substitute
products for hazardous materials used in indus-
trial processes and by consumers, we reduce the
overall harmful effects to both humans and the
environment.
GIS, Pollution Prevention,
and Public Health
Some examples of how GIS might be used to
further pollution prevention goals and activities
include: using GIS to overlay environmental,
health, and demographic data to identify com-
munities and individuals at disproportionate
risk of environmental exposures; targeting
communities for education about pollution in
their community and opportunities for preven-
tion; providing technical assistance or resources
to businesses by conducting environmental
audits and finding less toxic alternatives for
inputs in their production processes; and con-
vincing local elected officials to restrict growth
or zoning in certain geographic areas if that
growth is not sustainable and would increase
pollution or create other public health hazards.
GIS is also an excellent tool for describing
groundwater sources, potential contamination,
and potentially affected populations.
GIS is an excellent tool to characterize pollution
sources and other health information, which in
many cases is not known or easily understood.
GIS can be used to locate pollution sources
impacting the community, such as sanitary
sewer outfalls, landfills, underground storage
tanks, urban runoff from impervious surfaces,
agriculture, and chemical storage facilities.
Pollution prevention planning in the targeted
areas can then help to address such environmen-
tal and public health risks.
In addition to being an important pollution
prevention tool, GIS has many other applica-
tions for local health departments. Among these
are: identifying children at risk for lead poison-
ing, finding the quickest route for nurses and
outreach workers making home visits, targeting
children for immunizations, and defining
eligibility for medical screening (e.g., when a
plant has released a toxic plume). It can also be
used in conjunction with NACCHO's Assess-
ment Protocols for Excellence in Public Health,
Unking together health information from a
variety of different databases to recognize where
public health interventions would be cost-
effective and require action.
GIS can assist with projects at all stages, includ-
ing advancements in surveillance, assessment,
allocation of resources, increased access to
information, exposure information, spatial and
relational data analysis, and presentation of
data.
Issues GIS can address
GIS can address current and future data require-
ments and analysis. Looking toward the 21st
century, each community should have the
capability to link together health information
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GIS, Pollution Prevention, and Public Health
from a variety of different databases
(e.g., those of state and local public
health agencies, the U.S. Environ-
mental Protection Agency Toxic
Release Inventory (TRI), hospitals,
and managed care plans) and to
recognize data patterns where
public health interventions would
be cost-effective and require action.
GIS is likely one of the major keys to
successful development of this
capability.
GIS makes it easy to comprehend
large volumes of data and explore
spatial relationships, patterns,
trends, and outliers that otherwise
might go unnoticed. GIS also makes
it easy to "zoom in" from a map
showing the spatial pattern of
information from a large area to a
more detailed view of a small area of
interest.
In addition, GIS can be used as a
revenue generator. Many local
health departments must track all
waste sites and other hazards and
provide this information to those
investigating land purchases or
areas for development. Geocoding
this information (assigning latitude
and longitude or street addresses for
use in a GIS), and charging a fee for
service will reduce valuable staff
time spent on paper chases, provide
accurate and professional maps for
customers, and possibly lead to
other services for the community.
Revenue can potentially fund part
or all of a GIS position(s) and pro-
vide resources to the public in a
timely and cost-efficient manner.
GIS also strategically increases
planning and analysis capabilities
and reduces information redun-1
dancy, decreasing the amount of
time it takes to assemble data that
was previously retrieved manually
Generating Revenue from GIS
at the Albuquerque Environmental
Health Department, NM
Creation of the Site Environmental Audit (SEA)
Information System was motivated by increased
demand for record search services — especially data
for environmental site audits — during a period of
severe financial cuts at the City of Albuquerque. To
address a greater demand for services with limited
funding and personnel resources, the Albuquerque
Environmental Health Department, initiated a state-
of-the-art application utilizing the city's existing
geographic information system to provide quick and
accurate data from state and federal databases for
sites in question. The SEA provides consultants
with a set of custom maps and a series of reports for
the sites that are annotated on the maps. The fol-
lowing maps are included:
>• A one-mile map that provides data on
Superfund sites and hazardous waste handlers,
including NPL, CERCLIS, RCRA, SARA Title
III, and landfills or illegal dumps sites.
^- A half-mile map that indicates any leaking
underground storage tanks.
>• A quarter-mile map that includes RCRA genera-
tors as well as registered underground storage
tanks that are not leaking. The base layer
(information) for this map is land use, so that
the client can easily recognize whether the site
is within a predominantly residential or com-
mercial neighborhood.
>• A natural features and infrastructure map
contains information on the 100-year flood-
plain, approximate depth to groundwater,
arroyos, city wells, and sanitary sewer lines.
The SEA processes an average of 230 requests for ;
service per year and has generated an average of
$37,500 per fiscal year.
For more information on Albuquerque Environmen-
tal Health Department's revenue generating pro-
gram, contact Gloria Cruz, GIS Program Coordina-
tor, at (505) 768-2603 or e-mail at gcruz@cabq.gov.
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National Association of County & City Health Officials
and analyze and publish it from days to hours
or minutes.
Limitations of GIS
This fact sheet is intended only as a starting
point. Local health officials should carefully
think about their needs and investigate available
options before making an investment in GIS.
GIS is a significant investment in time as well as
money and requires trained personnel to oper-
ate the system. Training cannot be limited to
only the technical specialist who maintains the
system, but must also be provided to those who
use it to help them perform their everyday
work. One must realize that developing and
operating a GIS system is time intensive and the
quality of the results will take time, depending
on type of software used, available data, and
results sought.
Some local health officials may find non-GIS
mapping solutions (See Epilnfo and EpiMap
under GIS Software) to be more than adequate
for their needs. In addition, new and improved
products are available each year—some at a
lower cost. Although GIS is an innovative and
useful tool, there is still much to learn about
how to appropriately use it in public health
practice. While maps illustrate problem areas,
they also can lead people to identify hotspots
that are not real. Collaboration with an epidemi-
ologist is recommended to avoid misuse of GIS
and incorrect conclusions.
Because GIS can provide pinpoint accuracy of
data on a map, confidentiality is another impor-
tant issue that must be addressed when using
private information or developing information
that may impact members of the community
(however, given a population of sufficient size,
data may be displayed in less detail to conceal
identities—such as by providing information by
block or larger area).
How it Works: System Design
A GIS consists of five key components: hard-
ware, software, data, people, and methods.
Hardware is the computer terminal and its
parts, such as the microprocessor, monitor, hard
drive, etc. (see computer requirements under
Addendum). There is no single computer
software program that is "the GIS" software
program. Rather, a computer software program
is classified as GIS when it is able to perform
GIS functions. These include: zooming from a
large area to a small area and vice versa; chang-
ing projections; searching and retrieving data;
measuring distances, areas, and events within a
boundary area; drawing buffer zones (e.g., rings
around points); and Unking information such as
tables, charts, and photos to points on maps.
Maps are made up of data with geographically
referenced identifiers organized in different data
layers, also called themes or coverages (see Data
under Addendum for more information). Each
layer consists of similar geographic features,
such as property zones, household income,
hazardous waste handling sites, emergency
evacuation zones around hazardous waste
handlers, etc. Maps are created by overlaying
data layers.
One of the most important parts of a GIS are the
trained people who operate the system. People
who use GIS include technical specialists who
maintain systems, people who develop methods
to solve problems, and everyday users who use
it to complete their work. The final component
of a GIS is the methodology, or practices, rules,
or procedures applied to utilize the GIS func-
tions and analyze data. Methodology will vary
according to field, training, and organizational
standards.
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GIS, Pollution Prevention, and Public Health
Dais
GIS
Ptoople
Mgtftocb
Types of Applications
Software applications range from simple to •
complex and cost from $300 to $18,000. Similar
to advancements in _______
word processing
and database
software in the last
ten years, GIS
software has also
come into its own,
allowing for differ-
ware is offered for free for viewing map (shape)
files (see resources for more information).
Examples of software applications are given in
NACCHO's GIS Pollution Prevention Case Stud-
"Without a dedicated, trained staff, GIS
can end up being like that expensive piece
of exercise equipment stored in your base-
ment or garage/'
—Daniel L. Partidge, RS, BS, Environmental Health Supervisor,
Reno County Health Department, KS
les.
Time
Perhaps more important than GIS software is
the ability to have dedicated time to work on the
GIS program. GIS work, like many specialties,
requires formal instruction and extensive on-
the-job self-training and orientation to software
and available data sets. The GIS specialist's
work is comprised mainly of responsibilities in
acquisition, development, and maintenance of
databases; conducting geographic analysis;
documenting and presenting results in visual
and written formats; providing needed project
planning and system quality assurance; and
working with all
areas of the health
department,
especially the
areas of epidemi-
ology and assess-
ment.
ent levels of exper- ___________
tise to be devel-
oped and applied. Some of the most current GIS
software will allow you to use it as it is or
customize it to meet your needs. Software
ranges from very simple with little expertise
needed that may also offer few options for
customizing data and maps, to user friendly
desktop GIS that can be customized and ma-
nipulated, to the programmer's GIS software
which can be customized to analyze and present
data in any format needed.
However, if all you want to do is view census
data, you can view it for free through the Cen-
sus Bureau's Web site at http://
www.census.gov, or through the Bureau's
prototype viewer called Census Mapper. The
U.S. Environmental Protection Agency also
offers free maps of its Toxic Release Inventory
and other data on the Internet at http:/ /
www.epa.gov. In addition, Arc Explorer soft-
Costs
To get your pro-
gram off the ground and reduce costs, consider
interns or work-study agreements with nearby
university graduate programs to staff a small
start-up project. Funding with which you can
incorporate costs for staff time or hardware costs
may be available from federal and state agencies
such as the U.S. Environmental Protection
Agency, U.S. Department of Housing and Urban
Development, the Centers for Disease Control,
and your state departments of health and the
environment. Current hot topics areas include
environmental justice and source water protec-
tion. While an initial GIS software investment
can range from about $300 to $18,000, depend-
ing on what you want to do (e.g., put maps on
the Internet), additional purchases may be
needed to add on software components or
update to newer versions.
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National Association of County & City Health Officials
Sharing Resources Among
Agencies: Opportunities for
Communication and Cooperation
The full potential benefits of technology and
data can only be realized through intergovern-
mental and private sector cooperation, coordina-
tion, and partner- _______
ships. GIS technol-
ogy has taken such
large leaps forward
in the last few years
Many local governments have already
created agencies, offices or agreements to
coordinate agency I agency or county I city-
wide GIS development and data integra-
tion. Don't be left out.
in the area of data
accessibility and
management, that it
is now a resource """—"~"~""""~~"~"""
for integrating local
government data. By working with other agen-
cies, you can enhance GIS capacity and reduce
time and money needed to develop your GIS
resources. In addition, other local agencies, such
as public safety, planning, public works, tax
assessment, etc., may already be using GIS to
increase the efficiency and effectiveness of their
programs.
W«rer/W«tew«ter
Transportation
Police
Fire
Advantages of working with other agencies:
>• Sharing information can lead to better
service delivery for cooperating agencies.
For example, working with the transporta-
tion agency you may find that in order for
high-risk community members to take the
bus to local clinics, they must change buses
three times or walk a long distance. Im-
proved cooperation can lead to better bus
routes and cost effective sitings of future
clinics.
Many factors may influence which GIS
software package might be best for a specific
LHD. Of particu-
lar importance is:
what GIS equip-
ment is being used
by other units of
your state and
local government?
Some state and
-—'—'—"—"——— local governments
have started to standardize GIS equipment
to help reduce cost and to facilitate exchange
of GIS information between local govern-
ment agencies.
^- Integrating existing data between local
agencies will result in major benefits such as
increased capacity to support GIS technol-
ogy and services, reduced field work and
research time, improved customer service,
increased productivity, more professional
and detailed presentation of graphics, and
increased cross-agency cooperation and
support.
Define Your Needs
For many local health departments, a good
approach to GIS might be: 1) Start to gradually
learn more about GIS by subscription to infor-
mational newsletters such as the National
Center for Health Statistics's Public Health GIS
News and Information (newsletter available via e-
mail), and introductory readings or courses (see
resources); 2) Don't be the last local health
department to use GIS; 3) Start small; get hands
on experience with what GIS can do; demon-
strate a success; and then consider making a
more substantial investment; and 4) Take some
time to explore, learn, and talk to other local
health department and local government GIS
users in your community before making an
investment. GIS also is increasingly used in
business decision making (e.g., to determine
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GIS, Pollution Prevention, and Public Health
Central GIS Management for Local
Government, Good for all Involved
In 1984, the City of San Diego and County of San
Diego jointly initiated the Regional Urban Informa-
tion System (RUIS) project in response to the increas-
ing complexity of delivering efficient and effective
municipal services to the residents of this large and
growing region. The mission of the RUIS project was
to develop a highly integrated geographic information
system (GIS) designed to meet the needs of all city
and county activities that create or use geographic
information. RUIS' goals were: to improve productiv-
ity; reduce costs; provide access to accurate, timely
information for decision making; and, to improve
service to citizens.
Through the RUIS program, a highly integrated GIS
was created including data, software, hardware, and
administrative components necessary to operate a
successful GIS for the city and county. Much of the
data are maintained by various county and city de-
partments, including the county Environmental
Health Department, and are made available to all
participating departments through a distributed
network. The RUIS project helped improve decision
making and efficiency in local government by provid-
ing more timely information and eliminating redun-
dant activities and by re-engineering and automating
manual processes. RUIS is considered one of the most
successful multi-participant geographic information
system ever attempted and was presented the Exem-
plary System in Government Award by the Urban and
Regional Information Systems Association in 1995.
In 1997 a Joint Powers Agreement (JPA) between the
city and county formalized their partnership in GIS
by creating the SanGIS JPA. SanGIS is carrying on the
work already set in motion by RUIS by ensuring that
geogrphic data is maintained and accessible. Its
mission is to establish, maintain, and promote the use
of a regional geographic data warehouse for the San
Diego area and to assist in the development of shared
geographic data and automated systems which use
that data. For more information, call the SanGIS
Executive Director at (619) 702-0400, or search its Web
site at http://www.ruis.org.
customer location and buying
habits, and locate sites for
stores). Consequently, your
regional economic development
office or chamber of commerce
also may be an excellent source
of information about GIS.
Available Resources
The following resources are
compiled only as a starting point
for further research and is by no
means complete. Therefore, it
should not be your only refer-
ence. Any listing of information
and/or materials, software, and/
or data should not be construed
as an endorsement or recommen-
dation by NACCHO. Prices
listed are the normal commercial
price at time of publication.
However, special discounts or
additional costs may apply.
GIS Software
Software listed performs some or
all functions of a GIS program.
Listing format: software applica-
tion name, type, cost, website,
phone (Ph.).
0 Atlas GIS
' Desktop software
$795
http://www.esri.com
Ph. (800) 447-9778
y Arc Explorer
Viewing software
Free
http: / / www.esri.com
Ph. (800) 447-9778
El Arclnfo
Programming Software
$18,000
http://www.esri.com
Ph. (800) 447-9778
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National Association of County & City Health Officials
S Arc View CIS
Desktop Software
$1,200
http: / / www.esri.com
Ph. (800) 447-9778
SI Business Analyst (includes Arc View)
Desktop software
$11,000
http: / / www.esri.com
Ph. (800) 447-9778
SI HUD Community 2020
Desktop software
$249
http://www.hud.gov/commut
Ph. (800) 998-9999
SI Landview
Desktop Software
Free (http://www.rtk.net/landview/)
http://www.epa.gov/swerosps/bf/htrnl-
doc/lvfctcpo.htm
Ph. (800) 424-9386
S3 Map Info Professional
Desktop software
$1000
http: / /www.mapinfo.com
Ph. (800) 327-8627
SI Maptitude
Desktop Software
$395
http: / / www.maptitude.com
Ph. (617) 527-4700
Bl Epi-info and Epimap
Non-GIS software with some mapping
functions
Free on the Internet
http://cdc.gov/epo/epi/epiinfo.htm
Ph. (404) 639-0840
E-mail Lists
and Electronic Newsletters
H Subscribe to Public Health CIS News and
Information: a free e-mail newsletter from
the National Center for Health Statistics. To
subscribe, send email to: cmc2@cdc.gov.
5 Subscribe to the free Community 2020
listserve, called ppgis-scope. To sign-up see:
http: / / www.projectscope.org
H Subscribe to the free magazine, Business
Geographies, through web site: http://
www.geoplace.com/bg
Internet Resources
H Environmental Systems Research Institute
maintains an extensive list of resources on
GIS: http://www.esri.com
B Geoplace Warehouse sells books on general
and specific topics: https: / /secure.aip.com/
gisbooks / index.html
B GIS Master Bibliography Project provides a
comprehensive bibliography of GIS related
research and literature: http://
paradise.sbs.ohio-state.edu/resources/
B HDM's Virtual GIS Bookstore provides GIS
links and offers numerous GIS titles: http://
www.hdm.com/gisbooks.htm
B Improving Public Health Through Geographical
Information Systems..., Web Version 1.0,
December, 1997: http://www.uiowa.edu/
~geog/health
B National Pollution Prevention Roundtable:
http://www.p2.org/
B National Association of County and City
Health Officials: http://www.naccho/org
B Pollution Prevention Information Clearing-
house: http://www.epa.gov/opptintr/
library/libppic.htm
B U.S. Census Bureau provides information on
census data: http://www.census.gov/
B U.S. Geological Survey maintains a compre-
hensive list of links and resources: http:/ /
www.usgs.gov/network/science/earth/
gis.html
GIS Resources and References
£Q Clarke KC, McLafferty SL, and Templaski BJ.'
1996. "On Epidemiology and Geographic
Information Systems: A Review and Discus-
sion of Future Directions." Emerging Infec-
tious Diseases 2 (no 2): 85-92.
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GIS, Pollution Prevention, and Public Health
£3 Croner CM, Sperling J, and Broome FR. 1966.
"Geographic Information Systems (Gis):
New Perspectives in Understanding Human
Health and Environmental Relationships."
Statistics in Medicine 15:1961-1977.
ffl Gordon A, and Womersely J. 1997. "The Use
Of Mapping In Public Health And Planning
Health Services." Journal of Public Health
Medicine 19 (No 2): 139-147.
13 Lavin MR. 1996. Understanding The Census:
A Guide For Marketers, Planners, Grant Writers
and Other Data Users. Kenmore, New York:
Epoch Books, Inc.
B3 Popovich ML, and Tatham B. 1997. "Use of
Immunization Data and Automated Map-
ping Techniques to Target Public Health
Outreach Programs." American Journal of
Preventive Medicine 13 (Suppl 1): 102-7.
G3L Public Technology, Inc. 1997. .gis://the next
management tool. Explores why local govern-
ments should implement GIS and how they
can plan, fund, launch, and maintain suc-
cessful systems. See http://pti.nw.dc.us/
PubsnNews.htm, or call (301) 490-2188 for
more information
H Rushton G, and Armstrong MP. 1998. Im-
proving Public Health Through Geographic
Information Systems: An Instructional Guide to
Major Concepts and Their Implementation,
Version 2.0. CD-ROM, Cost $20 per copy,
orders of 10 or more $10 per copy. For more
information, http://www.uiowa.edu/
-geog/health; e-mail: gerard-
rushton@uiowa.edu; or fax: (319) 335-2725.
£3 U.S. Department of Housing and Urban
Development. 1997. Mapping Your Commu-
nity: Using Geographic Information to
Strengthen Community Initiatives.. Free guide
(#HUD-1092-CPD) by the, Office of Commu-
nity Planning and Development, call (800)
998-9999.
NACCHO
Pollution Prevention Publications:
£3 Drinking Water, Pollution Prevention, and Pub-
lic Health: A Matrix for Disease Prevention and
Environmental Protection. 1997. Provides pub-
lic health officials with an understanding of
how to integrate pollution prevention into
everyday activities, and to define other roles
health departments can play to reduce risks
through pollution prevention. The Guide is
an excellent educational tool for health depart-
ments and community residents. Available
online at: http://www.naccho.org/projects/
p2.html.
E3 Pollution Prevention and Public Health: A Uni-
fied Approach to Disease Prevention and Environ-
mental Protection. 1996. Illustrates the critical
link between pollution prevention, drinking
water and public health, and promotes steps
local health officials can take to reduce health
risks by helping to safeguard the nation's wa-
ter supply. Available online at: http://
www.naccho.org/projects/p2.html.
£3 Preventing Pollution in our Cities and Counties:
A Compendium of Case Studies. 1995. This
report describes how local governments are
employing innovative, low cost pollution
prevention strategies, available to both
members and non-members for $7.50.
To order, send a check or purchase order (or
number) to NACCHO, 1100 17th Street, NW,
Washington, D.C. 20036, or Fax to: (202) 783-
1583, Attention: Anissa Bradby; e-mail:
ABradby@naccho.org. Phone orders to (202)
783-5550, ext. 237.
Addendum
Data
Data that has a geographic reference is referred
to as geocoded data. To geocode data is to give it a
geographic reference. Any value that can be
attributed to a referenced point or area (for
example, property lines, zoning boundaries,
household income, exposures, roads, sewer
systems, auto body shops, wells, septic systems,
hazardous material handlers, and hospitals) can
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National Association of County & City Health Officials
be mapped using GIS. Data can also be dis-
played at different magnification levels, ranging
from a parcel of land, to city blocks, to multiple
counties, states or larger.
GIS data is stored in databases (ie., Microsoft
Access, Excel, dbase etc.) that are not unique to
the GIS software. Each record must have a
geographic reference (latitude and longitude or
a street address—if working with software that
allows this function) to be utilized by the GIS
software and placed on a map.
Availability of geo-coded public health data
needs careful consideration. The largest compo-
nent of "cost" in a GIS system can often be the
data, or getting "clean"" data in a form that can
be used in a GIS. Most software comes with a
limited amount of data and maps, such as
census information and maps of county bound-
aries in the U.S.
Data is available from federal, state and local
government, and commercial sources. Much of
the start-up data used in local government
applications is from federal government sources.
This includes U.S. Environmental Protection
Agency Toxic Release Inventory data, and
TIGER (census data) files from the Census
Bureau.
Commercial sources of data consists of value-
added products and vendors that will convert or
customize data to meet your project needs.
Value-added data products consist of data
available from the government Aat are custom-
ized and/or packaged with other data for
specific uses or requirements. While the U.S.
government and commercial industry has a
wealth of information available to you, your
first stop on your data search should be state
and local agencies that may have data and maps
already customized for your locality (see Sharing
Resources Among Agencies).
Eventually, you will want to have capacity to
prepare and analyze data from your local health
department and other community sources (e.g.,
you may need to convert your data to dBase
files and then geo-code your own data). In
10
addition, some data sources have flaws (even
TIGER files may not be perfect). It's best if a
local health department can collect and digitize
their own information whenever possible to
assure quality control—the quality of one's
output is only as good as the data used.
Choosing data is not as simple as purchasing'it
off the internet rack. It may be helpful if all data
is in the same scale (e.g., 1:24,000 meters, kilo-
meters, miles, etc), but the map projection
system must be the same (e.g., Universal Trans
Mercator). In terms of scale, if you would like to
do a very detailed study of an area, it is best to
use a smaller scale map. If the focus changes to a
larger scale, then there is no problem. However,
if a person starts off with a larger scale map and
wants to look at the area in greater detail
(smaller scale) then there will be a lot of extra
work to do.
Collecting and Plotting Data
Data can be purchased or collected in the field
and attributed to boundary areas on a map that
are already made and usually included in
software purchases, such as counties, zip codes,
census tracts, and by street address if the GIS
system you are using supports this function.
Local data can also be acquired through surveys
and field research. Data from surveys can be
attributed to street addresses, blocks, zip codes,
or other areas. Data can also be acquired in the
field by using the global positioning system.
Global positioning system (GPS) receivers are
used in the field to collect real-time data points
that can be easily recorded in a database for
development and customization of local maps.
GPS is a satellite-based navigation system
developed by the U.S. Department of Defense
(DOD) that allows land, sea, and airborne GPS
users to determine their three dimensional
position, velocity, and time 24 hours a day, in all
weather conditions, anywhere in the world. The
system depends on 24 satellites in orbit around
the earth. GPS receivers collect signals from
satellites in view and display the user's position,
velocity, and time as needed. GPS provides two
levels of service—Standard Positioning Service
(SPS) for the general public and an encoded
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GIS, Pollution Prevention, and Public Health
Precise Positioning Service (PPS) for the DOD.
SPS signal accuracy is intentionally degraded by
the DOD for the purpose of "national security"
through a process called Selective Availability
(SA). SA limits the accuracy of signals from
satellites by 100 meters horizontal and 156
meters vertical. The basic GPS unit is handheld
and costs $100 to $400 or more. However, more
sophisticated systems have evolved around the
SA limits to provide users with more accurate
data. These are differential GPS receivers and
surveying systems. Differential GPS receivers
are accurate to within three to ten meters if the
service is available in your area. Surveying
systems using two or more units working in
tandem provide accuracy of more than 1 cm for
the better models, and range in price from
$7,000 to $30,000 or more. The military is pre-
paring to do away with SA in the next ten years.
The Nuts and Bolts:
Hardware Requirements
It suffices to say that like most software require-
ments, system complexity correlates with system
capacity. Initial computer investment depends on
the computer equipment that you already have
available and what you want to do. For small
"beginner" projects and learning about GIS, the
computer equipment that you already have may
be more than sufficient. However, as projects start
to grow and become more sophisticated, a rela-
tively high-speed computer and capability to store
large amounts of data are advantageous.
The following are suggested minimum and
recommended computer requirements for free-
standing independent units; however, hardware
requirements vary with each software package,
and hardware technology is continually improv-
ing, making today's technology less expensive
tomorrow.
Suggested Minimum Requirements
•^ Industry standard personal computer with
at least a 486 MHz or higher Intel-based
microprocessor
•^ Hard disk with at least 144 MB or greater
capacity
^ 16MB of Ram
^ 3.5" floppy disk or CD ROM drive
^ capacity for additional disk or storage space
^ 17 MB of virtual memory
^ Video graphics adapter (VGA) or better
resolution monitor
^ Operating system of MS-Dos 5.0 or. higher,
Microsoft Windows 3.1, Windows for
Workgroups 3.11, Windows NT 3.51, or
Windows 95
Mouse
Printer
Recommended Requirements
^ 300 MHz or faster (for dealing with large
amounts of information) Pentium Processor
II with MMX Technology
^ Hard Disk with at least 4 GB EIDE hard
drive
^ 64 MB Ram memory
^ 12x EIDE CD ROM drive
•^ Back-up capability (e.g, Iomega ZIP 100 MB
IDE internal drive, LAN system back-up,
tape drive back-up, or CD ROM writer)
^ Video Board with 8 MB RAM
^ 17 inch viewable or higher graphic quality
color monitor
^ 56kbs Modem or ability to connect to
Internet
Options:
Color printer
Digitizer
NACCHO Information
The National Association of County and City
Health Officials (NACCHO) is the national voice
of local health officials and is dedicated to
improving and protecting the public's health by
increasing the capacity of local health depart-
ments (LHDs) to fulfill the core functions of
public health: assessment, policy development,
ar;d assurance. NACCHO serves all of the 2,932
LHDs nationwide; this includes county, city, and
district health departments. NACCHO's work
11
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National Association of County & City Health Officials
focuses on providing education, training and
technical assistance aimed at ensuring the
public's health. GIS is one tool that is used in
fulfilling this role. In addition, NACCHO serves
as a communication vehicle among local, state,
and federal public health and environmental
health agencies, allowing NACCHO to promote
pollution prevention and share successes.
NACCHO would like to thank the following
reviewers for their excellent comments and
review and notes that not all reviewers may
agree with all statements contained in this
document.
Members of NACCHO's
Environmental Health Committee:
Richard Brusuelas, MPH, Director, Bernililo
County Environmental Health Department, NM;
Lou Dooley, RS, MSEH, Director, Environment
Health Services, Southwest Washington Health
District, WA; Roslyn Hamilton, RS, MPH,
Director of Health, Bridgeport Health Depart-
ment, CT; Scott E. Holmes, MS, REHS, Chief,
Environmental Health Division, Lincoln-
Lancaster County Health Department, NE; Hm
McDonald, RS, MPH, Health Services Director,
Island County Health Department, WA; Ngozi
Oleru, PhD, Director, Office of Environmental
Health, Boston Public Health Commission, MA;
Frances B. Phillips, RN, MHA, Health Officer,
Anne Arundel County Department of Health,
MD; John Pickle, MSEH, Director, Weld County
Health Department, CO; Robert A. Tannis,
Assistant Director, Environmental Health,
Health and Human Services Department, City
of Houston, TX, and; Susan G. Zepeda, PhD,
Director, San Luis Obispo County Health
Agency.
Disclaimer: This guide has been produced for
\ informational purposes only as a service to
NACCHO members and the public health
community. Any listing of information and/
I or materials, software, and/or data should
not be construed as an endorsement or recom-
! mendation by NACCHO. NACCHO shall not
\ be held liable for any damages related to your
'. use of information and/or materials listed in
this fact sheet.
12
NACCHO Members
Fredric Cantor, DVM, MPH, Director of
Needham Board of Health, MA; Carl Kinkade,
MCRP (Cand.), GIS Coordinator, Lincoln-
Lancaster County Health Department, NE, and;
Dan Partridge, BS, RS, Environmental Health
Supervisor, Reno County health Department.
NACCHO's Project Officer
Danielle Fuligni, Project Manager, Pollution
Prevention Division, Office of Pollution Preven-
tion and Toxics, U.S. Environmental Protection
Agency.
Special thanks also go to Thomas B. Richards,
Public Health Practice Program Office, Centers
for Disease Control and Prevention who helped
a great deal in the preparation of this document.
NACCHO also thanks Phillip Bouton, who
wrote this document, with the assistance of Beth
Resnick and Michael Fraser, and Jill Conley for
layout.
This fact sheet was made possible through a
grant from the U.S. Environmental Protection
Agency, Office of Polluntion Prevention and
Toxics.
(Selected graphic images reprinted courtesy of
Environmental Systems Research Institute, Inc.
Copyright © 1995-1998 Environmental Systems
Research Institute, Inc. All rights reserved.)
Printed on recycled, chlorine-free processed
paper with environment-friendly ink. 9/98
NATIONAL
ASSOCIATION OF
COUNTY & Crrr
HEALTH OFFICIALS
11OO 17TH STREET, NW,
SECOND FLOOR
WASHINGTON, DC 2OO36
PHONE: (2O2) 783-555O
FAX: (202)783-1583
HTTP://WWW.NACCHO.ORG
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