Environmental Issues Flashcards
1
Q
Toxicants are linked to…
A
- Miscarriage
- IGR
- Low birth weight
- Preterm birth
- Birth defects
- Motor and cognitive delays
2
Q
Breathing Zone
A
- For an adult: typically 4-6’ above the floor
- A child is closer to the floor where heavier chemicals (i.e. mercury, large breathable particles) settle out
- Children are smaller than adults; their metabolic rate is higher than adults; they consume more O2
3
Q
Harmful Exposure Target Organs
A
- Poor fetal/childhood growth
- Diminished IQ
- Precocious puberty
- Small head size
- Diminished lung capacity
4
Q
Deadly Pediatric Poisons (Meds)
A
- CCBs
- TCAs
- Lomotil
- Opiates
- Salicylates
- Toxic ETOHs
- Sulfonylureas
- Camphor
- Clonidine and imidazoline
- Antimalarials
5
Q
Pesticide Poisoning
A
- Specifically organophosphates and carbamates
- Work by inhibiting cholinesterase
- Present with cholinergic Sx (coma/stupor, flaccidity, dyspnea, miosis, salivation, GI signs, clammy)
6
Q
Nicotinic Symptoms
A
- ** Days of the Week ***
- M ydriasis
- T achypnea
- W eakness
- T achycardia
- F asciculations
- Weekend (wee ones)
7
Q
Hydrocarbon poisoning
A
- Aliphatic: Kerosene, turpentine, lubricating oils, tar –> aspiration and pulmonary Sx
- Aromatic: benzene compounds –> hepatic toxicity and neurologic Sx
8
Q
Heavy Metal Toxicity
A
- Lead
- Mercury
- Arsenic
9
Q
Why is lead dangerous?
A
- More hand-to-mouth
- Play on floor
10
Q
Common Sources of Lead
A
- Paint and dust
- Soil
- Water
- Toys, vinyl miniblinds
- Pottery from foreign places
11
Q
Other Sources of Lead
A
- Keys
- Pewter
- Home remedies (Azarcon, Greta)
- Glaze on bathtubs
- Soil contaminated from gasoline
12
Q
S/S of lead toxicity
A
- Fatigue, irritablity, lethargy, paresthesias, myalgias
- ABD pain, tremor HA, vomiting, weight loss, constipation
- Loss of libido, motor neuropathy, encephalopathy, cerebral edema, seizures
- Coma, epiphyseal lead lines (growth arrest)
- Renal failure
13
Q
Toxicokinetics and Toxicodynmics of Lead
A
- Absorption:
- Lungs
- GI: Adults 20-30%; Children ~50% (inadequate intake of Fe, Ca, and total cal associated with higher Pb levels)
- Skin: inorganic NOT absorbed, organic absorbed
- Lead is carried bound to RBC
14
Q
Pharmacokinetics and Pharmacodynamics of Lead
A
- Distributed extensively throughout tissues: bone, teeth, liver, lung, kidney, brain, spleen
- Bones constitute a source of Pb storage and continued toxicity after exposure has ceased
- Pb crosses the blood brain barrier and concentrates in gray matter
- Crosses placenta
15
Q
Lead Levels
A
- Average ~2mcg/L
- Acceptable is 5mcg/L
- IQ/growth impaired at >10mcg/L
- Nerve damage at >20mcg/L
- Impaired Vd synthesis at >30mcg/L
- Hgb synthesis impaired at >40
- ABD pain and neuropathy at >50
- Encephalopathy, anemia, seizures, nephropathy at >100
16
Q
Neurotoxicity of Pb in Childhood
A
- MR in severe Pb intoxication
- Down 5pts in IQ for q 10mcg/L increase in Pb blood level
- Other adverse outcomes: aggression, hyperactivity, antisocial behaviors, learning disabilities
17
Q
Pb Screenings
A
- 12mo w/Hgb
- 24mo (levels typically higher)
- Once before 6yr if not done sooner
18
Q
Pb Toxicity Dx
A
- Evaluation of S/S
- CBC-diff
- Serum ferritin, TIBC
- ABD XR
- Whole blood Pb level
19
Q
Tx Pb Toxicity
A
- Environmental inspection/reduction
- Nutritional supplementation
- Chelation
- Nutritional Supplementation: Fe, Ca, phos, frequent foods
20
Q
Chelation
A
- BLL >70 or encephalopathy: hospital admit, parenteral chelator
- BLL >45: oral chelator
- BLL 25-45: if these levels persist despite environmental intervention, then treat
21
Q
Mercury
A
- Occurs in 3 forms: elemental (liquid, volatizes), inorganic (caustic, dermal exp), and organic (lipid soluble; GI, lungs, skin absorb)
- Contamination results from mining, smelting, and industrial discharge
- Can be found in fish, thermometers, dental amalgams, fluorescent light bulbs, disc batteries, electrical switches, folk remedies, chemistry sets, vaccines
22
Q
Elemental Mercury
A
- At high concentrations, vapor inhalation produces acute necrotizing bronchitis, pneumonitis, and death
- Long-term exposure effects include:
- Early: Insomnia, forgetfulness, anorexia, mild tremor
- Late: Progressive tremor, erethism (red palms, emotional lability, memory impairment
- Salivations, diaphoresis, renal toxicity
- ** Dental amalgams do not pose health risk
23
Q
Inorganic Mercury
A
- GI ulceration or perforation and hemorrhage are rapidly produced, followed by circulatory collapse
- Breakdown of mucosal barriers leads to increased absorption and distribution to the kidneys
- Acrodynia (pink disease) usually from dermal exposure –> maculopapular rash, swollen/painful extremities, peripheral neuropathy, HTN, renal tubular dysfunction
24
Q
Organic Mercury
A
- Toxicity occurs with long-term exposure and effects from the CNS (paresthesias, ataxia, general weakness, visual/hearing impairment, tremor/muscle spasticity, coma/death)
- Teratogen with Lg chronic exposure
- Infants may appear NL at birth but psychomotor retardation, blindness, deafness, and seizures develop over time
25
Q
Mercury: Prevention
A
- Elemental Mercury spills: 1) roll onto a sheet of paper and place in airtight container, 2) never use vacuum to prevent vaporization, and 3) consult with environmental cleaning company
26
Q
Arsenic: Sources
A
- Groundwater
- Mineral ores
- Industry: Semiconductor manufacturing; fossil fuels; treated wood; metallurgy; smelting and refining of metals; glass manufacturing; pesticides; herbicides, fungicides; anti-parasitic drugs; folk remedies
27
Q
Arsenic toxicity: S/S
A
- Thirst, HoTN, burning mucosa; N/V/D; ABD pain; hematemesis/hematochezia; hemolysis; pancytopenia, etc.
28
Q
Arsenic: Tx
A
- Gastric lavage
- Activated charcoal does NOT bind well with arsenic
- Bowel irrigation with polyethylene glycol
- skin decontamination
