1 Lead vs MTBE Toxicity StudyStudy carried out on adult earthworm Toxicity expressed in folds for comparison purpose Days of admin TEL Pb Ox MTBE Environmental Research Volume 92, Issue 3, July, 2003, pp 2008, 24 July

2 “وشهد شاهد من أهلها” “and a witness of her household bore witness”“Hidden History of Leaded Gasoline Reveals Industry Conspiracy to Conceal Dangers. Lethal Product Still Marketed Throughout The World.” 2008, 24 July

3 HEALTH HAZARDS OF LEAD Moh’d Khalili, MBChB, DCH, MSc., JMCC Directorate of Environmental Health, MOH, Amman, Jordan. 2008, 24 July

4 Lead in Roman Empire, 1st Century B.C.Inexpensive reliable metal suitable for many everyday uses Water network, kitchen ware, cosmetics, paint pigment, spermicide, food seasoning, food & wine adulteration, lead coin, counterfeit silver & gold coin,……etc Romans were aware of lead deleterious health effect: Madness, gout, stillbirths, sterility, impotence, ……………..death Yet, they held to the belief: limited exposure = limited risk 2008, 24 July

5 Lead in USA, 20th Century 1921: TEL acknowledged as an excellentanti-knock additive to gasoline, : TEL toxic effects encountered and warned of, yet ignored, WHY ? 1927–1986: Extensive use of leaded gasoline. 1976 –19??: Phasing out leaded gasoline 2008, 24 July

6 Roman Empire, 1st Century:Lead Usage Rate Roman Empire, 1st Century: 550 gm / Person / Year USA, 1980: 5,221 gm / Person / year 2008, 24 July

7 Sources of Environmental Contamination with Pb1- Leaded gasoline 2- Solid waste incineration, 3- Coal and oil combustion, 4- Iron and steel production, 5- Lead smelting, 6- Copper smelting, 7- Soldering cans 8- Ore crushing & grinding, 9- Portland cement industry 10- Storage battery industry, 11- Lead glass industry, 12- Crop enhancer 2008, 24 July

8 Leaded Gasoline, A major source of environmental contamination with Pb1- Combustion of leaded Gasoline = 88% of the total Pb emissions to atmosphere. 75% of added Pb is emitted in vehicles & engines exhaust, mostly as Pb particulates, to a lesser extent as gaseous Pb 2- Losses during filling of gas tanks, ? GS attendants’ exposure 3- Evaporation during accidental spills (unchanged TEL), ? GS workers 4- Release during production of gasoline &TEL 2008, 24 July

9 Fate of lead Particulates in the atmosphere1- Deposition on the ground, 2- Dispersion in soil and water, “Lead reservoir in soil” 2008, 24 July

10 Phasing Out Leaded Gasoline: a Priority* Lead toxicity, a well known fact, * Dispersive nature of fine particulates emitted, * Entry into human body is easy, * Children vulnerability. * Deposition on soil creates long standing hazards. 2008, 24 July

11 Leaded gasoline phased out, yet lead is still there:* Lead emissions from certain industries, * Soil reservoir, * Lead accumulation in bone, Pb half life 6-10 yrs, lead mobilization in certain conditions, examples * Fine lead particulates in the atmosphere. 2008, 24 July

12 Entry of Lead into the Body thru:1- Respiratory system: Inhalation 2- Digestive system: Ingestion 3- Skin: Contact. 2008, 24 July

13 Fate of Inhaled Lead Particulates* Inhaled lead PM <0.5 μm are barely retained in lungs, * larger particulates are coughed up & swallowed, * 90% of ≤0.5 μm particulates are retained * Absorption of retained Pb in lungs is efficient & complete. 2008, 24 July

14 Lead Ingestion Ingestion of dust and soil: hand to mouth activityIngestion is the major source of lead poisoning in children: Ingestion of dust and soil: hand to mouth activity Consuming contaminated fruits and vegetables Swallowing coughed out large particulates Drinking contaminated water “old water network” 2008, 24 July

15 Transcutaneous AbsorptionMinimal absorption thru intact skin. “↑Injury” Inorganic lead is not absorbed, TEL (organic compound) may enter thru skin TEL in the body → inorganic lead 2008, 24 July

16 Lead Toxicity; age groups mostly affected1- Children ˂ 6 years are the most vulnerable: * Hand to mouth activity and pica, * Children growing systems absorb more lead, * Children CNS is more sensitive to damage. * More prone than adults to nutritional defeciences. 2- Workers in lead – risk occupations. 2008, 24 July

17 Lead Level Blood, Adults, general population: ˂ 20 mcg / dlBlood, workers in Lead risk occupation: ˂ 40 mcg / dl Blood, workers who intend to have children: ˂ 30 mcg/dl Blood, children: ˂ 10 mcg / dl Blood, children: 40 mcg / dl necessitates treatment. Air, workplace: PEL mcg / cubic meter, averaged over 8 hours / workday Air, public exposure: ???? Mcg / cubic meter. 2008, 24 July

18 Lead Poisoning, Patient’s HistorySymptoms are not specific GIT: abdominal pain, anorexia, constipation, vomiting. Neurobehavioral: Inattentiveness, distraction, recklessness, learning problems. Reproductive: ↓ sex drive, impotence, sterility, stilbirths General: fatigue, weakness, dizziness. “Rare in children” 2008, 24 July

19 Signs are non specific too, severity variesLead Poisoning, Signs Signs are non specific too, severity varies Buccal stains, gingival lead line Pallor (picture of anemia) Hyperactivity Signs of increased IC pressure: impaired consciousness, bradycardia, hypertension, respiratory depression, papilledema, coma Hyperuricemia, aminoacidurea, gout, renal failure. 2008, 24 July

20 Lead Poisoning, Investigations* Blood tests Blood sugar: ? cause of coma CBC: anemia, basophilic stippling BLL EP Delta ALL * Urine tests Routine MSU 2008, 24 July

21 Lead Poisoning, InvestigationsX-Ray: lead flakes in abdomen, lead lines in extremities CT scan: brain edema, increased IC pressure, structural lesions in the brain 2008, 24 July

22 Lead Poisoning, Treatment** Role of Patient and Patient’s Family Prevention of further exposure, Correction of faulty conditions generating lead, Correction of nutritional deficits, Follow ups, repeat BLL tests, Parents: Keep in mind, the possibility of lead poisoning in children with ………… Request BLL whenever in doubt. ** Medications Professional doctors ONLY assigned to carry out. ll 2008, 24 July

23 References Information retrieved on 18 thru 23 July, 2008 from articles and information available on the following websites: 2008, 24 July

24 شكراً THANK YOU 2008, 24 July