Heavy metals

1. Ecological Risk
Assessment of
Heavy Metals PRESENTED BY
AFIFA QASIM (2)
FAKIHA SAFDAR (12)
QURAT UL AIN (17)
H.ARSALNA (30)
BISMAH AREEJ (35)
TAYYAB USMAN (41E )
AFIFA GOHAR (48)

2. Jens
Martensson
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Heavy metals
• Heavy metals are a group of metals and metalloids that have relatively high
density and are toxic even at ppb levels
• Essential elements are often required in trace amounts in the level of 10–15
ppm and are known as micronutrients.
• EPA and the International Agency for Research on Cancer (IARC) have classified
heavy metals as human carcinogen.
• Because of their high degree of toxicity, arsenic, cadmium, chromium, lead, and
mercury rank among the priority metals that are of public health significance.
• Heavy metals are also considered as trace elements because of their presence in
trace concentrations (ppb range to less than 10ppm) in various environmental
matrices

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Martensson
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Classified into two categories:
essential and nonessential heavy metals
• Essential HMs are those required by living organisms for carrying out
the fundamental processes like growth, metabolism, and development
of different organs. There are numerous essential heavy metals like Cu,
Fe, Mn, Co, Zn, and Ni required by plants as they form cofactors that
are structurally and functionally vital for enzymes and other proteins.
• Nonessential heavy metals like Cd, Pb, Hg, Cr, and Al are not required
by plants, even in trace amounts, for any of the metabolic processes.
Table 6.1 depicts the manifestation of toxicity induced by copper, zinc,
cadmium, and lead to different plant species.
• There is a very narrow range of concentrations between beneficial and
toxic effects

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Martensson
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Properties
• Unlike organic pollutants, heavy metals are nonbiodegradable and have
tendency to accumulate in living beings.
• Heavy metals induce detrimental effects, including developmental toxicity,
cell death, neurotoxicity, oxidative stress, and immunotoxicity.
• Owing to their bioaccumulative potential along the food chain, high toxicity,
prevalence, and persistence in the environment, heavy metals have become a
major public health concern.
• Heavy metals commonly accumulate in living organisms because of the non-
biodegradable, toxic nature of heavy metals, and non-thermo degradable.

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Martensson
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Sources
• Although heavy metals are naturally occurring elements that are found
throughout the earth’s crust, most environmental contamination and human
exposure result from anthropogenic activities such as mining and smelting
operations, industrial production and use, and domestic and agricultural use of
metals and metal-containing compounds metals are released into the
environment by both natural and anthropogenic sources such as industrial
discharge, automobiles exhaust, and mining.
• Their multiple Industrial, domestic, agricultural, medical and technological
applications have led to their wide distribution in the environment; raising
concerns over their potential effects on human health and the environment.
• Industrial sources include metal processing in refineries, coal burning in power
plants, petroleum combustion, nuclear power stations and high tension lines,
plastics, textiles, microelectronics, wood preservation and paper processing
plants.

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Martensson
Routes Of Exposure

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Martensson
• effects of exposure to heavy metals can vary
depending on the type of metal, the route of
exposure, and the duration and level of exposure.
• Some heavy metals, such as lead and mercury, can
have serious health effects even at low levels of
exposure.
• Other heavy metals, such as copper and zinc, are
essential to human health in small amounts but can
be toxic at higher levels.
Routes Of Exposure
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Martensson
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Toxicokinetic
Toxicokinetic is
essentially the
study of "how a
substance gets
into the body and
what happens to
it in the body."

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Martensson
ABSORPTION
• Inhalation: Heavy
metals can be inhaled as
fumes, dust, or mist.
This is a common route
of exposure for workers
in industries that involve
metal processing,
smelting, and welding.
Toxicokinetic Of Heavy Metal
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Martensson
• Ingestion: Heavy metals
can enter the body through
the gastrointestinal tract,
either by consuming
contaminated food or water
or by accidental ingestion.
• Dermal Contact: Heavy
metals can also enter the
body through the skin, for
example, through contact
with contaminated soil or
through the use of
cosmetics or other personal
care products that contain
heavy metals.
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Martensson
• DISTRIBUTION
• Some heavy metals, such as lead and cadmium, have a high
affinity for bone and can accumulate in bone tissue over time.
Other heavy metals, such as mercury, tend to accumulate in the
kidneys and brain.
• Some heavy metals, such as iron, are essential for the body's
normal function and are tightly regulated. Others, such as lead,
cadmium, and mercury, have no known essential function in the
body and can accumulate in the body over time with repeated
exposure.
Toxicokinetic Of Heavy Metal
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Martensson
• METABOLISM
heavy metals, such as lead, cadmium, and mercury,
have no known essential function in the body and can
accumulate in the body over time with repeated
exposure. These metals can disrupt normal cellular
processes and can bind to various proteins, enzymes,
and nucleic acids, altering their function.
Toxicokinetic Of Heavy Metal
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Martensson
• Lead: Lead can bind to several enzymes and proteins
in the body, causing them to malfunction.
• Cadmium: Cadmium can bind to metallothionein, a
protein that regulates the uptake and elimination of
heavy metals, which can lead to the accumulation of
cadmium in the body.
• Mercury: Mercury can bind to and inactivate enzymes
in the body, and can also form a complex with a
specific protein called metallothionein, which can lead
to the accumulation of the metal in the body.
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Martensson
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Toxic
Mechanisms
of Five Heavy
Metals:
Mercury,
Lead,
Chromium,
Cadmium,
and Arsenic

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Martensson
• Excretion
• Excretion of heavy metals refers to the process by which the
body eliminates these metals from the body. The excretion of
heavy metals varies depending on the specific metal and can
occur through urine, feces, sweat, or hair.
• Urine: Heavy metals such as lead, cadmium, and mercury can
be excreted through urine. However, the efficiency of excretion
through urine can vary depending on the individual's health
status, genetics and nutritional status.
Toxicokinetic Of Heavy Metal
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Martensson
• Feces: Some heavy metals such as lead and cadmium
can be excreted through feces.
• Sweat: Heavy metals such as cadmium and lead can be
excreted through sweat. However, the efficiency of
excretion through sweat is generally low compared to
urine and feces.
• Hair: Heavy metals can also be excreted through hair,
but it's not a common route of elimination, and hair
analysis is not a reliable indicator of exposure.
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Martensson
MERCURY
LEAD
CADMIUM
ARSENIC
Health effects of
Heavy Metals
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Martensson
Among lead's well-
known developmental
health effects
is stunting of skeletal
growth in children.
Moreover, lead is known
to delay fracture
healing and may
contribute to
osteoporosis.
Lead
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Permissible Standards for lead
are
• The lead standards
establish a permissible
exposure limit (PEL) of 50
μg/m3 of lead over an
eight-hour time-weighted-
average for all employees
covered.
• The calculated IRLs are 2.2
micrograms (µg) per day
for children and 8.8 µg
per day for females of
childbearing age.

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Martensson
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Martensson
Mercury majorly cause Minamata
disease
It may
• Deteriorates nervous system
• Impairs hearing, speech, vision, and gait
• Cause involuntary muscles movements
• Corrodes skin and mucous membranes
• Cause chewing and swallowing to become difficult
Mercury
OSHA: The legal
airborne permissible
exposure limit (PEL)
is 0.1 mg/m3
averaged over an 8-
hour work shift
Symptoms include
• Tremors
• Insomnia
• memory loss
• neuromuscular
effects
• Headaches
• cognitive and
motor
dysfunction.

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Cadmiu
m
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Cadmium have many adverse effects
on different parts or organs of body
Respiratory system
• Pneumonia
• Destruction of mucous membrane
Kidney
• kidney stones
• Glomerular and tubular damage
Reproductive system
• Testicular necrosis
• Estrogen like effects
• Infection of steroid hormones
Skeletal system
• Loss of bones density
• Itai itai disease

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Martensson
Permissible level of arsenic
• The permissible exposure limit for arsenic is no greater than 10 micrograms of
inorganic arsenic per cubic meter of air, averaged over any 8 hour period for a 40
hour workweek [OSHA 2001; NIOSH 2005].
• The current drinking water standard, or Maximum Contaminant Level (MCL), from the
U.S. Environmental Protection Agency (EPA) is 0.010 mg/L or parts per million
(ppm).
Arsenic
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Martensson
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24. Heavy metals

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Martensson
The concentrations of heavy metals (Cr, Cd, Hg, Cu, Zn, Pb and As) in
sediment, and fish were investigated in the middle and lower reaches of
the Yangtze River, China. The samples were collected from the main
river and lakes in the Yangtze River basin at 17 sites in the middle reach
and from 10 sites in the lower reach. In total, 27 water and sediment
samples were collected.
HM concentration in sediments:
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Martensson
The lakes had the highest mean concentrations of Hg, Pb, Cr, Cu, Zn,
and OM, while the lower reach of the main river had the highest mean
concentrations of Cd, As, TN, and TP. Mean concentrations of metals in
the middle reach were relatively lower. This may be due to the
downstream movement of water. The heavy metal concentrations in the
sediments were higher in the lakes than in the river. We suggest that this
was due to the higher flow disturbance in the river that led to re-
suspension and downstream movement of pollutants.
HM in sediments
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Martensson
• The potential ecological risk index (RI) was introduced to assess the
degree of heavy metal pollution in sediments, according to the
toxicity of heavy metals and the response of the environment
• Hg posed a considerable ecological risk at five sites and a
moderate risk at two. Additionally, Cd and As also posed relatively
high ecological risks in these areas. The high ecological risks of
these three heavy metals in freshwater ecosystems are
consequences of their high toxic-response factors.
Ecological risk assessment
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28. Jens
Martensson
• In terms of their spatial distribution, sites with moderate or
considerable potential ecological risk indices for Hg and Cd
were located near to large cities (Wuhan, Nanjing, and
Jiangyin), or ports (Chenglingji), or lakes with high human
activity (Dongting Lake and Donghu Lake).
• The highest potential ecological risk indices for As were found
in the lower reach, mainly downstream of Poyang Lake.
• For other metals (Pb, Cu, Cr, and Zn), the potential ecological
risk indexes were low. The potential ecological risk indices for
single regulators indicated that the severity of pollution of the
seven heavy metals decreased in the following sequence: Hg >
Cd > As > Cu > Pb > Cr > Zn
Ecological risk assessment
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29. Jens
Martensson
• Two sites among twelve in the middle reach of the main river
exhibited moderate or considerable ecological risk. Most of the
lakes and sites in the lower reach of the main river posed
moderate or considerable ecological risk. The RI values were
clearly related to the degree of anthropogenic disturbance.
• For example, the Tian’ezhou wetland, which is a natural
conservation area in China, had the lowest heavy metal
concentrations and minimal potential ecological risk, while
sites near to big cities (such as Wuhan, Nanjing, and Jiangyin)
had relatively high ecological risks.
Ecological risk assessment
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30. Jens
Martensson
According to the potential ecological risk index, Hg represented
a moderate risk at 7.4% of sites, and a considerable risk at 18.5%
of sites; Cd posed a moderate risk in 37% and As in 22% of the
regions. The ecological risk for all factors (RI) showed that 7.4%
of sample sites belonged in the category of considerable risk,
and 33% were of moderate risk.
In accordance with the high potential ecological risk of the
metals Hg, Cd, and As in sediments, the four metals Pb, Cd, Hg
and As, were the most important with respect to health risks
Conclusion
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Heavy metals in Landfill Leachate

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Martensson
Introduction:
• Heavy metals contained in waste have for years been disposed of in dumps and
landfills.
• Organic matter in landfill leachate binds heavy metals strongly and colloidal matter has
a high affinity for heavy metals. The presence of organic complexes and colloidal-
bound heavy metals in leachate-polluted groundwater affects the total concentration
as well as the behavior of heavy metals in the aquifer.
• The purpose of this paper is to determine the distribution of heavy metals between
different species in leachate-polluted groundwater sampled down gradient of an
actual landfill.
• Organic bound species were determined by a speciation procedure involving an
anion-exchange column and the distribution of heavy metal species in the inorganic
part of the truly dissolved fraction was calculated using a geochemical speciation
model.

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Martensson
Sampling Site:
• Two landfill-leachate polluted groundwater samples were collected down gradient at
two different depths of 7 m with area strongly anaerobic with a high content of organic
matter.
Sampling procedure:
• One leachate-polluted groundwater sample 2 m below the groundwater table with a
Teflon tube.
• Other with stainless steel tube 5 m below with low oxygen diffusion coefficient.
• Turbidity, pH, specific conductivity and temperature were monitored during the
pumping to ensure equilibrium before the samples were collected and no samples
were collected until all these indicator parameters had reached steady values.

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Martensson
Methodology:
Size Fractionation:
• The spiked leachate-polluted groundwater samples were separated into size fractions
using the pore sizes 0.40,0.010 and 0.001 mm.
Chemical Analysis:
• Specific conductivity, pH and alkalinity were measured immediately after the filtration
in all size-fractions.
Calculation of heavy metal species:
• A geochemical model was used in order to estimate dissolved inorganic species in the
samples.
Anion Exchange Technique:
• Reference solutions were used to caught only organic species and determined by TOC
content.

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Martensson
Heavy Metal Distribution:
• Four categories (inorganic colloidal metal species, , organic colloidal metal species,
organic dissolved metal species, inorganic dissolved metal species.
• For Cd, Cu and Pb the fractions of organic species dominated (>59%). The inorganic
colloidal species were 1-41% ,dissolved inorganic species only constituted a very small
part.
• Ni and Zn the dissolved inorganic species were 30% L1 of the metal content and for
about 70% in L2. In both groundwater samples 2-40% of the total content of Ni and Zn
was free metal ions, whereas the organic fractions contained 15-62% of the total
content of Ni and Zn.

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Martensson
Conclusion:
• Colloidal matter was found in spiked leachate-polluted groundwater
samples, but the truly dissolved fraction (<0.001 mm) constituted 79-84% of
the total solids probably as inorganic salts and small organic molecules.
• Most of the colloids were small and consisted to a large extent of organic
matter. Fe, Ca, S and Cu were found in the colloidal fractions. This indicated
that both clay type particles, organic matter and precipitates were present
in sample.
• Speciation by an anion-exchange technique showed that the heavy metals
complexed strongly with the organic matter in leachate-polluted
groundwater, especially with respect to Cd, Cu and Pb. More than 60% of
Cd, Cu and Pb were found to be organic species.
• Results suggests except for Zn, heavy metals are strongly associated with
small-size colloidal matter, which is to a large extent organic matter. This
implies that the behavior of heavy metals in the environment may differ
from the behavior expected for truly dissolved heavy metal

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38. Jens
Martensson
Assessment of heavy metals to determine ecological risk
through measurement of biotic response in plants can
provide information on the extent of bioavailability of
metals and their influence on the natural state of
aquatic ecosystem.
A significant aspect of this lagoon is a series of events
that might have occurred during the last four decade.
Assessment of ecological risk by determination of heavy
metals in benthic sediment and investigation of
physiological response against heavy metals in
Avicennia marina leaves is the main objective of this
study. A. marina is the only mangrove species found
throughout the Rabigh lagoon.

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Martensson
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 Materials and methods
1. Study area
2. Experimental design and sample collection
3. Preparation of samples
4. Determination of heavy metals in plants and sediments
5. Determination of heavy metals in plants and sediments
6. Determination of sediment pollution
7. Ecotoxicological risk
8. Bioaccumulation of metal in mangrove
9. Analysis of antioxidant enzymes in mangrove A. marina
10. Data analysis

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Conclusions:
1. A. marina was evaluated in this study in relation to possible stress caused by heavy
metals in eight stations investigated at the Rabigh lagoon, Red Sea.
2. There was a significant correlation between heavy metal concentrations in A. marina
leaves and mangrove ecosystem sediments, except for Cu and Cd. This is an indication of
fluctuation in the bio concentration factor of both plants and sediment.
3. In total, the results of our findings established deterioration of the sediment in a gradual
pattern which has a potential for negative impacts on the biogeochemical cycle, with
potentially lethal consequences for biodiversity survival. Consequently, there is a need for
periodic and regular monitoring of the pollution status in this ecosystem, through the use of
biochemical markers in the mangrove A. marina

41. Heavy Metals

42. Why

43. To protect human health and
the environment by limiting
exposure to heavy metals,
which can have negative
effects on both.

44. Who

45. • US EPA: United States Environmental Protection
Agency
• WHO: World Health Organization
• OSHA: The Occupational Safety and Health
Administration,USA
• NEBOSH: The National Examination Board in
Occupational Safety and Health, UK
• UNECE: The United Nations Economic Commission for
Europe
• USFDA: United States Food and Drug Administration
• EU: European Union
• FOA: Food And Agriculture Organization of United
States

46. How

48. There are various laws and regulations in place to control the release
of heavy metals into the environment. These include;
• EPA sets limits on the amount of heavy metals that can be present in
drinking water, air, and soil.
• The Clean Air Act
• The Clean Water Act
• The Resource Conservation and Recovery Act
• Maximum contaminant levels (MCLs) for certain heavy metals,
such as lead and arsenic
• OSHA and NEBOSH sets standards to limit exposure at work place
• US food and Drug Administration FDA has set stands for permissible
limits in finished food and drinking water.

49. • The European Union also has regulations in place to control
the release of heavy metals;
• The Heavy Metals in Fertilizers Regulation
• The REACH Regulation (Registration, Evaluation,
Authorisation and Restriction of Chemicals)
• Regulations in place to limit the amount of heavy metals in
consumer products, including toys and jewelry
• Sets limits on heavy metal emissions from industrial
sources
• Maximum levels for a number of heavy metals in food, such
as cadmium in cocoa and chocolate products.
PANALITIES

50. UNCE -Protocol on Heavy Metals
• On 24 June 1998,The Executive Body adopted the Protocol in Aarhus
(Denmark)
• It targets three particularly harmful metals: cadmium, lead and mercury
• The basic obligations, Parties have to reduce their emissions for these
three metals below their levels in 1990
• To cut emissions from industrial sources, combustion processes, waste
incineration, stationary sources, and other mercury-containing products
(batteries, electrical components, measuring devices, fluorescent
lamps, dental amalgam, pesticides and paint.

51. • suggests best available techniques (BAT) for these sources, such
as special filters or scrubbers for combustion sources or mercury-
free processes. In addition, the Protocol requires Parties to phase
out leaded petrol.
• This came into enforcement in 29 December 2003
• In 2012, they introduced flexibilities to facilitate accession of new
Parties
• update guidance on best available technologies (BAT)
• Amendments entered into force on 8 February 2022.
• In 2013, the Minamata Convention on Mercury was
adopted, a treaty negotiated under the auspices of the
United Nations Environment Programme (UNEP).
• Building on the 1998 Protocol on Heavy Metals, the Minamata
Convention raised the profile of mercury to the global level.

52. Pakistan
The Pakistan Environmental Protection Agency, is an
executive agency of the Government of Pakistan managed
by the Ministry of Climate Change
• Punjab Environmental Protection Agency-PEPA
• Balochistan Environmental Protection Agency-BEPA
• Environmental Protection Agency Khybar Pakhtunkhoa
–EPA KPK
• Environment Protection Agency Azad Jammu and
kashmir-AJK EPA

54. Thank
You