BMP for Lead <strong>at</strong> Outdoor <strong>Shooting</strong> RangesLow permeability reduces <strong>the</strong> amount ofhistorical leaching <strong>and</strong> increases <strong>the</strong> probabilityof <strong>the</strong> presence of basic (+pH increasing)minerals th<strong>at</strong> can precipit<strong>at</strong>e out of solution ingroundw<strong>at</strong>er or cause <strong>the</strong> lead to bond to <strong>the</strong>clay. All of <strong>the</strong> basic calcium <strong>and</strong> rel<strong>at</strong>edminerals generally will have been removed from<strong>the</strong> clean silica s<strong>and</strong> <strong>and</strong> gravel soils, so <strong>the</strong>lead in solution in groundw<strong>at</strong>er in <strong>the</strong>se typesoils can move long distances (miles) through<strong>the</strong> ground rel<strong>at</strong>ively unchanged.Soil Chemistry - The more basic minerals likecalcium <strong>and</strong> magnesium th<strong>at</strong> are present in soilsalong <strong>the</strong> p<strong>at</strong>hways through which <strong>the</strong>groundw<strong>at</strong>er moves, <strong>the</strong> gre<strong>at</strong>er <strong>the</strong> leadprecipit<strong>at</strong>ion (removal) r<strong>at</strong>e. Lead should movein solution only a short distance (a few feet)through a s<strong>and</strong> composed of calcium shellfragments, but could move in solution longdistances (miles) through clean quartz s<strong>and</strong>.Depth to Groundw<strong>at</strong>er - In areas ofgroundw<strong>at</strong>er discharge such as river flood plains<strong>and</strong> most fl<strong>at</strong> areas, <strong>the</strong> groundw<strong>at</strong>er surface isoften a few feet below <strong>the</strong> surface. Remember,<strong>the</strong> shorter <strong>the</strong> distance traveled, <strong>the</strong> gre<strong>at</strong>er <strong>the</strong>risk th<strong>at</strong> <strong>the</strong> lead will migr<strong>at</strong>e into <strong>the</strong>environment. Shallow depth to groundw<strong>at</strong>er isindic<strong>at</strong>ive of higher risk for lead to reach <strong>the</strong>w<strong>at</strong>er.pH of Groundw<strong>at</strong>er - Although o<strong>the</strong>r factorsinfluence solubility of lead in w<strong>at</strong>er, a good rule ofthumb is th<strong>at</strong> lead will precipit<strong>at</strong>e out of solutionwhen <strong>the</strong> pH or alkalinity of w<strong>at</strong>er is gre<strong>at</strong>er <strong>the</strong>nabout 7.5. But, lead dissolved in acidgroundw<strong>at</strong>er may travel many miles withoutchange.Health Effects of Lead Exposure on RangesLead poisoning is a serious health risk. Athigher concentr<strong>at</strong>ions, it is dangerous to peopleof all ages, leading to convulsions, coma <strong>and</strong>even de<strong>at</strong>h. At even very low concentr<strong>at</strong>ions, itis dangerous to infants <strong>and</strong> young children,damaging <strong>the</strong> developing brain <strong>and</strong> resulting inboth learning <strong>and</strong> behavioral problems. Figure 1-1 describes <strong>the</strong> effects of exposure to lead onchildren <strong>and</strong> adults.Federal, st<strong>at</strong>e <strong>and</strong> local actions, including banson lead in gasoline, paint, solder <strong>and</strong> many o<strong>the</strong>rlead-containing products, have resulted insignificant reductions in average blood-leadlevels. Despite <strong>the</strong>se advances, <strong>the</strong> number oflead-poisoned children remains alarmingly high.Children living in older homes may be exposedto lead in peeling paint or paint dust. Childrencan also come in contact with lead in soil <strong>and</strong>with lead dust carried home on <strong>the</strong> clothing ofparents.On ranges, inhal<strong>at</strong>ion is one p<strong>at</strong>hway for leadexposure since shooters are exposed to leaddust during <strong>the</strong> firing of <strong>the</strong>ir guns. Becausewind is unlikely to move heavy lead particlesvery far, airborne dust is generally considered apotential thre<strong>at</strong> only when <strong>the</strong>re are significantstructures th<strong>at</strong> block air flow on <strong>the</strong> firing line.Under such conditions, <strong>the</strong> hygiene <strong>and</strong> o<strong>the</strong>rpractices proposed by <strong>the</strong> NRA for indoorshooting ranges in <strong>the</strong>ir “Source Book” areapplicable to outdoor ranges.Range workers may also be exposed to leaddust while performing routine maintenanceoper<strong>at</strong>ions, such as raking or cleaning out bullettraps. Owners/oper<strong>at</strong>ors may want to protect<strong>the</strong>se workers by requiring <strong>the</strong>m to wear <strong>the</strong>proper protective equipment or dampening <strong>the</strong>soil prior to work.Ano<strong>the</strong>r exposure route for lead <strong>at</strong> outdoorranges is ingestion by direct contact with lead orlead particles. For example, lead particlesgener<strong>at</strong>ed by <strong>the</strong> discharge of a firearm cancollect on <strong>the</strong> h<strong>and</strong>s of a shooter. Theseparticles can be ingested if a shooter e<strong>at</strong>s orsmokes prior to washing his/her h<strong>and</strong>s aftershooting. The rel<strong>at</strong>ive risk of lead exposure topeople in a well managed facility is low.Detrimental effects due to elev<strong>at</strong>ed lead levelscan also be found in animals. Excessiveexposure to lead, primarily from ingestion, cancause increased mortality r<strong>at</strong>es in c<strong>at</strong>tle, sheep<strong>and</strong> w<strong>at</strong>erfowl. For example, w<strong>at</strong>erfowl <strong>and</strong>o<strong>the</strong>r birds can ingest <strong>the</strong> shot, mistaking it forfood or grit. W<strong>at</strong>erfowl, in particular, are highlysusceptible to lead ingestion. This is a concern<strong>at</strong> ranges where shooting occurs into or over<strong>Chapter</strong> I - Page I-4
BMP for Lead <strong>at</strong> Outdoor <strong>Shooting</strong> RangesEffects on <strong>the</strong> Human Body from Excessive Exposure to LeadIf not detected early, children with rel<strong>at</strong>ively low levels of lead (as low as 10microgram/deciliter for children) in <strong>the</strong>ir bodies can suffer from:- damage to <strong>the</strong> brain <strong>and</strong> nervous system,- behavior <strong>and</strong> learning problems (such as hyperactivity <strong>and</strong> aggressiveness),- slowed growth,- hearing problems,- headaches, <strong>and</strong>- impairment of vision <strong>and</strong> motor skills.Adults can suffer from:- difficulties during pregnancy,- reproductive problems in both men <strong>and</strong> women (such as low birth- weight, birth defects <strong>and</strong> decreased fertility),- high blood pressure,- digestive problems,- neurological disorders,- memory <strong>and</strong> concentr<strong>at</strong>ion problems, Brain or Nerve Damage- muscle <strong>and</strong> joint pain, <strong>and</strong>- kidney dysfunction.Hearing ProblemsSlowed GrowthDigestive ProblemsLead affects <strong>the</strong>body in many waysReproductive Problems(Adults)Figure 1-1: Effects on <strong>the</strong> Human Body from Excessive Exposure to Lead<strong>Chapter</strong> I - Page I-5
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