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American Journal of   
Environment and Climate (AJEC)

Ecological and Health Risks of  Heavy Metals to the Residents affected by a Volcanic 
Eruption in the Philippines
Genevee M. Banta1*, Cristina C. Salibay1

Volume 4 Issue 2, Year 2025
ISSN: 2832-403X (Online) 

DOI: https://doi.org/10.54536/ajec.v4i2.4212
https://journals.e-palli.com/home/index.php/ajec

Article Information ABSTRACT

Received: December 12, 2024

Accepted: January 16, 2025

Published: April 25, 2025

Volcanic eruption can be a source of  heavy metal contamination and such contamination 
may cause certain risks to the environment and to those who are exposed to the volcanic 
contents. This study aimed to determine the ecological and health risks from heavy metal 
exposure in the soil after a volcanic eruption. The agricultural soil samples were collected 
from Cuenca and Talisay, Batangas and Tagaytay City, Cavite, and were processed for arsenic, 
cadmium and mercury detection and quantification. The detected metal concentrations 
were compared to the standard values of  the Department of  Environmental and Natural 
Resources for arsenic and United States Environmental Protection Agency for cadmium 
and mercury while the ecological and human health risks were assessed by computing for 
the potential ecological risk, hazard quotient and hazard index, respectively. Arsenic was the 
only heavy metal with high mean concentration in the soil samples of  Talisay, Batangas and 
Tagaytay City, Cavite while cadmium and mercury in the soil were within the acceptable level 
in the three municipalities. The soil from Talisay, Batangas had two-fold arsenic increase 
while the samples from Tagaytay City, Cavite had one-fold arsenic elevation. The soil’s post-
volcanic eruption’s arsenic contamination was probably due to the direction of  the wind 
during the eruption and groundwater contamination. Low ecological risk and no human 
health risk were observed despite the recent arsenic concentration in the soil. A two-fold 
increase in arsenic concentration in the soil will not yet cause ecological and human health risk.

Keywords
Metal Contamination, Natural 
Calamity, Soil Pollution

1 De La Salle Medical and Health Sciences Institute, Philippines
* Corresponding author’s e-mail: geneveebanta@gmail.com

INTRODUCTION 
Volcanic eruption as a source of  heavy metals is less 
recognized than anthropogenic sources since it is 
less commonly observed and experienced. Volcanic 
eruptions caused deleterious effects on humans and 
the environment, such as burns, respiratory problems, 
destruction of  houses and buildings and damaged crops 
(Horwell et al., 2020). The gases from a volcanic eruption 
and the elements in the volcanic ash may contaminate 
the environment and subsequently affect the health of  
living organisms. Acid rain is usually observed during 
and after a volcanic eruption. Its acidity promotes 
plant uptake of  metals (Kim et al., 2010; Jenkins et al., 
2015). Most of  the local studies about heavy metals in 
the environment are related to anthropogenic sources 
(Buagas et al., 2024; Cortez & Ching, 2014). Due to the 
limited local studies about the assessment of  heavy metals 
after a natural calamity, the study aimed to determine the 
potential ecological and human health risks from heavy 
metal exposure in the soil of  the municipalities that were 
affected by Taal Volcano eruption. 

LITERATURE REVIEW
The ashes contain several heavy metals that may alter the 
normal growth and development of  crops and animals. It 
may even accumulate in these organisms and may affect 
the food chain. Cadmium, mercury, arsenic and lead were 
detected in the environment. They can be ingested and 
taken up by fishes and other living organisms. Increasing 

environmental concentration of  these heavy metals 
contributes to the accumulation and transfer in the food 
chain (Martinez et al., 2011).
The common routes of  entry of  heavy metals in the 
human body are through the inhalation, ingestion and 
skin penetration (WHO, 2007). Mercury, lead, cadmium 
and arsenic are the known toxic heavy metals. Mercury 
has several forms and each form has its own modes of  
entry in the body. Elemental mercury is the vapor form 
that may gain access to the brain and kidneys after its 
initial injury to the respiratory system. Inorganic mercury 
is the metallic mercury that mainly accumulates in the 
kidneys. Methylmercury is the most significant form 
of  mercury since it may cause illness through any of  
the following routes: inhalation, ingestion and skin 
penetration (ATSDR, 1999). Aside from mercury, arsenic 
is also a toxic heavy metal that causes health effects after 
its ingestion. It acute effects are mainly gastrointestinal 
manifestations such as difficulty in swallowing, 
vomiting and organ injury. In chronic arsenic exposure, 
carcinogenic effects are observed in the skin, lungs, 
kidneys and bladder (US EPA, 2001). Another metal that 
affects gastrointestinal tract is cadmium. Cadmium may 
cause gastrointestinal and/or neurologic symptoms when 
an individual ingests contaminated vegetables and foods 
(Sharma et al., 2015). Respiratory and renal problems are 
also detected in individuals with exposure to cadmium. 
Prolonged cadmium exposure may even lead to cancer 
since its biological half-life is 30 years (ATSDR, 1990). 



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In the Philippines, provinces with significant heavy metal 
exposure are those that are exposed to mining industries 
(BanToxics, 2011). Aside from anthropogenic activities, 
heavy metal exposure after volcanic eruption should 
also be performed to determine the level of  pollutant 
contamination after the calamity.

MATERIALS AND METHODS
This study evaluated the ecological and health risks 
from exposure to mercury, arsenic, and cadmium after 
the 2020 Taal volcanic eruption. The soil samples were 
collected from seven locations in Talisay, Batangas, six 
locations in Tagaytay City, Cavite and one location in 
Cuenca, Batangas. The latter has the least number of  
collection sites for soil assessment since it represented 
the municipalities that are less affected by the 2020 Taal 
volcano eruption.  The soil samples were collected from 
either the garden or backyard of  the house of  a resident.  
A total of  1,000 grams of  soil were collected in each location 
from an approximate depth of  10cm. The samples were 
placed in a properly labelled polyethylene bag containers. 
Three replicate soil samples were collected from each 
location and were sent to a laboratory for processing and 
quantification of  mercury, arsenic and cadmium. The soil 
samples were stored at room temperature and were dried 
prior to its processing in a laboratory. The soil samples was 
processed and underwent cold vapor atomic absorption 
spectrometry for mercury detection and quantification 
while Manual hydride generation Atomic absorption 
spectrophotometry (AAS) and direct air-acetylene flame 
were used in the detection and measurement of  arsenic 
and cadmium in the soil samples, respectively. The results 
were presented in mean concentration. 

Mathematical Expressions and Symbols
Ecological Risk Assessment
The geoaccumulation index, enrichment factor and 
potential ecological risk index were used in assessing the 
ecological risk in the polluted soil.
The geoaccumulation index (Igeo) was used to determine 

the degree of  heavy metal pollution or contamination in 
the agricultural soil (Muller 1969). It was computed using 
this equation
Igeo = log2 (Cn/1.5 Bn)
where Cn refers to the estimated concentration of  heavy 
metals n and Bn as the background value in the soil. The 
background values in the soil were based on DENR 
AO2019-17 standard values for arsenic and based on 
the local studies of  Posadas et al. (2022) and Nolos et al. 
(2022) for mercury and cadmium concentration and it 
is as follows: mercury=2.19 ppm, arsenic=2.0 ppm and 
cadmium=0 ppm.
Meanwhile, the enrichment factor (EF) was also 
determined, and was identified the degree of  metal 
enrichment in the soil- from natural or anthropogenic 
activities. It was computed using this equation (Barbieri 
2016):
EF= (Metal/RE)soil/(Metal/RE)background
where RE refers to the value of  reference element based 
on DENR AO 2019-17 standard values for arsenic and 
the cadmium and mercury concentration of  a local study. 
An EF value of  <2 indicated deficiency to minimal 
enrichment, 2<EF<5 signified moderate enrichment, 
5<EF<20 was interpreted as significant enrichment, 
20<EF<40 indicated very high enrichment and EF>40 
extremely high enrichment.
Since this study has detected a single element in the soil, 
potential ecological risk factor for a specific element was 
computed but not the potential ecological risk index. The 
computation and toxic response factor were based on 
Hakanson (1980) using the following equation:
Potential ecological risk factors (Eri) for a specific element
Eri=Tri x Ci

f
where EEri, potential ecological risk factor for a specific 
heavy metal i, were computed using the toxic response 
factor Tri and contamination factor Ci

f. The Tri of  the 
heavy metals were as follows: Mercury= 40, Arsenic= 10 
and Cadmium= 30. The results were interpreted using 
the geoaccumulation index, Eri and PERI classification 
of  Hakanson (1980) as seen in Table 1.

Table 1: Classification of  ecological risk based on geoaccumulation index, potential ecological risk factor and index
Igeo value Risk classification Eri value Risk 

classification
PERI value Risk 

classification
Igeo ≤ 0 Practically unpolluted <40 Low risk ≤150 Low risk
0 ≤ Igeo ≤ 1 Unpolluted to moderately 40–80 Moderate risk 150 < PER ≤ 300 Moderate risk
1 ≤ Igeo ≤ 2 Moderately polluted 80–160 Considerable Risk 300 < PER ≤ 600 Considerable risk
2 ≤ Igeo ≤ 3 Moderately to strongly 

polluted
160–320 High risk PER > 600 High risk

3 ≤ Igeo ≤ 4 Strongly polluted ≥320 Very high Risk
4 ≤ Igeo ≤ 5 Strongly to extremely 

polluted
Igeo > 5 Extremely polluted

*Eri and PERI classification of  Hakanson (1980)



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Human Risk Assessment
Non-Carcinogenic Risk Assessment
The noncarcinogenic risk of  heavy metals in soil was 
established by computing for hazard quotient (HQ) and 
hazard index (HI). HQ was computed using this equation 
(Chonokhuu et al., 2019):
HQ= average daily dose or ADD/RfD or reference dose 
of  heavy metals in mg/kg/day
where average daily dose (ADD) referred to the daily 
dose of  heavy metal exposure in contaminated soil while 
reference dose of  heavy metals in mg/kg/day (RfD) 
referred to estimate of  persistent heavy metal exposure 
by the affected residents. The RfD of  arsenic was based 
on Ma et al. (2019) and the RfD per pathway were as 
follows: ingestion = 3.00 x 10-4 , inhalation= 5.00 x 10-5 
and dermal= 3.00 x 10-4. If  the hazard quotient <1, 
there was no potential health effects but if  the value was 
>1, there was potential health effects from exposure to 
contaminated soil. 
Aside from hazard quotient, hazard index (HI) was also 
computed to determine the total noncarcinogenic risk 
for each metal. It was computed by adding the hazard 
quotient for each metal and the study used this equation:
HImetal1=HQing + HQdermal + HQinh
The hazard quotients for each metal were added and were 
interpreted as follows: An HI value equal to or less than 
1 signified the absence of  non-carcinogenic risk from 
heavy metal exposure in contaminated soil but an HI 
value of  more than 1 indicated that there was a potential 
noncarcinogenic risks from an exposure to contaminated 
soil.

Carcinogenic Risk Assessment of  the Soil
Carcinogenic risk from heavy metal exposure in the soil 
was also determined and it was computed using this 
equation (Ma et al., 2019):
CR= ADD x SF
where CR referred to the carcinogenic risk from an 
exposure to a specific metal while SF was the cancer 
slope factor of  a specific metal. The SF of  arsenic 
based on pathway (Ma et al. 2019) were the following: 
ingestion= 1.5, inhalation= 15.1 and dermal= 3.66. It 
was interpreted as follows:  (a) CR less than 1 x 10-6 was 
interpreted as having no carcinogenic risk; (b) a CR value 
of  more than 1 x 10-6 but less than 1 x 10-4  or  1 x 10-

6<CR<1 x 10-4 signified that the metal exposure in the 
soil was within acceptable levels and had lesser chances 
of  carcinogenic risk; and (c) CR>1 x 10-4 indicated that 
there was significant potential of  carcinogenic risk from 
an exposure in contaminated soil. It was computed using 
Microsoft excel.

RESULTS AND DISCUSSION
Heavy Metal Concentration in the Soil
The arsenic concentration in the soil of  Talisay, Batangas 
and Tagaytay, Cavite have two- to three-fold increase 
and one- to two-fold elevation than the reference value, 
respectively, while the arsenic in the soil of  Cuenca, 

Batangas is maintained within the reference value (Table 
2). Meanwhile, cadmium and mercury concentration in 
the soil of  the three municipalities remains within the 
reference value. 
Martinez-Villegas et al. (2022) reported that volcanic 
contents were carried by the wind towards the northeast 
side of  Taal volcano, where Talisay, Batangas is situated, 
during the 2020 volcano eruption. However, the direction 
of  the wind redirected towards the southwest side of  the 
volcano and it blew lesser ash content than the actual 
volcanic eruption. The volcanic contents are known to 
be comprised of  elements and even heavy metals that 
can be harmful to those who will be exposed (Jenkins 
et al., 2015). Since volcanic contents is blown towards 
the northeastern side of  the volcano during the actual 
eruption, most of  the ashes might have settled on the 
ground of  Talisay, Batangas. Meanwhile, Tagaytay City, 
Cavite is the municipality that is located beside Talisay, 
Batangas and it has also been exposed during the 
eruption. Given this information, these municipalities 
had been greatly exposed during the volcanic eruption 
but it is Talisay, Batangas which is likely to have obtained 
more ashes than Tagaytay City, Cavite. 
Aside from the direction of  the wind, earthquakes 
were also observed during the eruption and such event 
may have disturbed the other soil contents. Broken 
glasswares were observed in some of  the collection 
sites in Talisay, Batangas. Between Talisay and Tagaytay, 
Talisay has a significantly high arsenic concentration, 
and these glasswares may have also contributed to the 
soil contamination. The heat from the environment may 
react with the glasswares which will trigger the release 
of  arsenic. This concept may also explain the arsenic 
in the soil of  the municipality. Aside from the actual 
observation of  the soil, the groundwater of  Talisay, 
Batangas was discovered to be contaminated by arsenic 
in the study of  Apostol et al. (2022). They discussed that 
it is possible that these water from wells have access to 
the volcanic contents. This contaminated groundwater 
may also have contributed in the arsenic contamination in 
the soil of  Talisay, Batangas as it flows through the land. 
The direction of  the wind, the shaking of  the ground 
during earthquakes and groundwater contamination are 
the possible sources of  the elevated arsenic in the soil of  
the two municipalities especially Talisay, Batangas.
Anthropogenic sources is also a source of  metal 
contamination and may have contributed in the 
elevated arsenic concentration in the soil of  the two 
municipalities. Fertilizers have been applied in some of  
the soil collection sites of  Talisay, Batangas. Wuana and 
Okieiman (2011) mentioned that fertilizers and pesticides 
are made-up of  arsenic and such chemicals may take 
several months before it is eliminated from the land. 
In the same study, they also discussed that burning of  
fuels may produce dust particles that contains arsenic. In 
relation to the study, the soil in some of  the collection 
sites in Talisay, Batangas have been treated with fertilizers. 
Moreover, the soil collection sites in Talisay, Batangas and 



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Tagaytay, Cavite is located at least 50 meters away from 
the roadside. These factors may have also enhanced the 

arsenic concentration in the soil of  the two municipalities 
aside from the natural sources.

Table 2: Comparison of  detected heavy metal concentration in the soil of  different municipalities to and its reference values
Municipality Arsenic Cadmium Mercury

Mean (ppm) Reference 
value (ppm)

Mean 
(ppm)

Reference 
value (ppm)

Mean (ppm) Reference 
value (ppm)

Talisay, Batangas 5.26
2.0 (DENR)

<0.03
0.075 (USEPA)

<0.08
1.8  (US EPA)Tagaytay, Cavite 3.94 <0.03 <0.08

Cuenca, Batangas 1.92 <0.03 <0.08

Table 3: Comparison of  the ecological risk assessment of  arsenic-contaminated soil of  the affected municipalities 
of  Taal volcano eruption

Cuenca Tagaytay Talisay
Igeo -0.64 0.40 0.81
Interpretation of  Igeo Practically unpolluted Unpolluted to moderately 

polluted
Unpolluted to moderately 
polluted

Enrichment factor (EF) 0.96 1.98 2.63
Interpretation of  EF Deficiency to minimal 

enrichment
Deficiency to minimal 
enrichment

Moderate enrichment

Potential ecological risk of  
arsenic (Eri)

9.6 19.75 26.3

Interpretation of  Eri Low risk Low risk Low risk

Ecological Risk Assessment
The soil samples of  Tagaytay, Cavite (Igeo=0.40) and 
Talisay, Batangas (Igeo=0.81) were classified as unpolluted 
to moderately polluted while Cuenca, Batangas has 
practically unpolluted soil (Igeo=-0.64). In terms of  
enrichment factor, the soil of  Cuenca, Batangas and 
Tagaytay City, Cavite were classified as having deficient to 

minimal enrichment because its enrichment factor is 0.96 
and 1.98, respectively, which are less than <2 (reference 
value). Despite having the minimal differences in other 
aspects of  ecological risk assessment, the soil from all 
three municipalities has low ecological risk for having 
arsenic in its soil (Table 3).

The metals that were recognized to have moderately 
to strongly polluted the environment were cadmium, 
chromium, mercury, lead and arsenic, with their 
maximum Igeo ranging between 2.7 to 6.2 (Radomirovic 
et al., 2020). In contrary, Chen et al. (2021) discovered that 
arsenic concentration from different lands with plant 
species regardless of  abundance and from a soil that is 
located in residential area demonstrated a non-polluted 
soil. Moreover, a strong to severe ecological risks is 
observed in a land with significant vehicular exposure 
and land manipulation. Like the result of  Chen et al. 
(2021), the finding of  this study also has a low ecological 
risk in arsenic-contaminated soil In this study, the soil 
samples were collected from a land that is located from 
either of  the following: with minimal vehicular exposure 
and/or directly from the backyard of  a residential 
house. Moreover, no industrial companies were located 
nearby or surrounding the collection sites. The study of  
Radomirovic et al. (2020) showed an increased enrichment 
factor (2.4 to 12) when compared to the reference value 
of  less than 2 and their soil were collected from an area 
with industrial leakage. Meanwhile, Ahmad et al. (2021) 
also detected a moderately heavy metal- contaminated 
and -polluted soil from a landfill.  This signifies that the 

possibility of  heavy metal contamination and pollution 
in the soil will depend on the location of  soil collection 
and the amount of  exposure to chemicals or discharges 
from industrial companies. In relation to the study, the 
soil collection site of  Cuenca is close to Taal Lake and it 
would require 1,500 steps before reaching the roadside. 
Due to the absence of  exposure to anthropogenic 
activities, the enrichment factor in Cuenca, Batangas 
and Tagaytay City, Cavite demonstrate that the arsenic 
can be from the earth’s crust. Meanwhile, the moderate 
enrichment in Talisay, Batangas was due to the natural 
and anthropogenic sources that have been identified. The 
identified anthoropogenic sources of  arsenic in the soil 
of  Talisay, Batangas were fertilizers, glassware and smoke 
from vehicles. This study showed that there is still low 
ecological risk despite an arsenic concentration of  up to 
three-fold elevation in the soil. This demonstrates that 
such concentration is not yet harmful to the environment.

Human Health Risk Assessment
Non-carcinogenic risks from an exposure to the soil of  
the three municipalities demonstrated a hazard quotient 
and hazard index values of  <1 and they signified that 
an exposure to arsenic-contaminated soil do not pose 



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a potential health effect and risk to both adult and 
children regardless of  point of  entry in the body (Table 
4).  Moreover, there is still no possibility for residents to 

develop cancer from an exposure to arsenic-contaminated 
soil based on the carcinogenic value of  less than 1 from 
the soil of  Cuenca, Tagaytay and Talisay.

Table 4: Non-carcinogenic and carcinogenic risk assessments from a possible exposure to arsenic-contaminated soil 
after the Taal volcano eruption
Non-Carcinogenic Risk

Age group Cuenca Tagaytay Talisay
Hazard index (HI) Adult 1.7 x 10-4 3.3 x 10-4 4.5 x 10-4

Children 1.0 x 10-4 2.1 x 10-4 2.8 x 10-4

Interpretation Absence of  non-carcinogenic risks
Carcinogenic Risk

Adult 1.2 x 10-9 2.4 x 10-9 3.2  x 10-9

Children 3.5 x 10-8 7.2 x 10-8 9.6 x 10-8

Interpretation No chances of  carcinogenic risks

Health risk from an exposure to arsenic is most likely to 
occur through ingestion and less of  the other pathways. 
However, it is through ingestion of  arsenic-contaminated 
water that both non-carcinogenic and carcinogenic 
health risks are identified and most likely to be observed. 
Children are more exposed than adults especially when 
they are in an area near a roadside and/or industrial 
companies and oral route is considered as the common 
pathway of  their exposure (Riaz et al., 2022).
Arsenic exposure cannot cause an immediate effect in the 
health of  a living organism, instead, it would require a 
prolonged exposure to it (Lou et al., 2010). In the study 
of  Apostol et al. (2022), the groundwater was discovered 
to be contaminated with arsenic. Given this information, 
the groundwater can be one of  the means of  human 
exposure. In terms of  arsenic-contaminated soil, the only 
way for humans to ingest arsenic is through the crops 
that grew in it. The current arsenic concentration in the 
soil of  Tagaytay City, Cavite and Talisay, Batangas will not 
yet pose noncarcinogenic and carcinogenic risks which 
means that it is still not harmful to the exposed residents. 

CONCLUSION
The study discovered that the soil from Cuenca, Talisay 
and Tagaytay were unpolluted to moderately polluted, 
have low to moderate contamination and have low 
potential ecological risk from arsenic. The location of  the 
soil collection contributed to this result. There is lesser 
possibility for the soil to cause a potential ecological risk, 
to be polluted and contaminated by arsenic when the 
soil is taken from an area that is devoid and distant from 
anthropogenic sources. The soil samples of  Talisay had 
other environmental factors such as fertilizers, broken 
glasswares and minimal exposure to vehicular smoke 
that led to moderate enrichment of  the soil. Thus, a 
combination of  environmental exposure to chemicals and 
actual soil collection sites affect the enrichment factor of  
an area. The soil may not directly cause a non-carcinogenic 
and carcinogenic risks to a person but we cannot totally 
eliminate the possibility of  arsenic exposure through 

ingestion of  the crops. The current arsenic concentration 
in the soil of  Talisay, Batangas and Tagaytay City, Cavite 
will not yet cause any significant harm to the environment 
and to the exposed residents.

Acknowledgements
I would like to give my deepest gratitude to the barangay 
health workers and local officials for their assistance 
during the soil collection; and to Atty. Percival Mendoza 
and Mrs. Charlene Edgel Mendoza for their help and 
assistance during the sample collection and other related 
technical assistance; and to Dr Darylle Cesar Hilapo for 
his assistance during the ocular inspection.

REFERENCES
Ahmad, W., Alharthy, R., Zubair, M., Ahmed, M., Hameed, 

A., & Rafique, S. (2021). Toxic and heavy metals 
contamination assessment in soil and water to evaluate 
human health risk. Scientific Reports, 11(1), Article 12489. 
https://doi.org/10.1038/s41598-021-94616-4

Apostol, G., Valenzuela, S., & Seposo, X. (2022). Arsenic 
in groundwater sources from selected communities 
surrounding Taal Volcano, Philippines: An exploratory 
study. Earth, 3(1), 448–459. https://doi.org/10.3390/
earth3010027

Agency for Toxic Substances and Disease Registry. 
(1990). Case studies in environmental medicine: Cadmium 
toxicity. https://www.atsdr.cdc.gov

Agency for Toxic Substances and Disease Registry. 
(1999). Public health statement: Mercury (CAS#: 7439-97-
6). https://www.atsdr.cdc.gov

Ban Toxics. (2011). Chasing mercury: Measuring mercury levels 
in the air across the Philippines. https://www.bantoxics.
org

Barbieri, M., Sappa, G., & Nigro, A. (2015). Soil 
contamination evaluation by enrichment factor (EF) 
and geoaccumulation index (Igeo). Senses Sci. https://
iris.uniroma1.it/retrieve/e383531e-668d-15e8-e053-
a505fe0a3de9/Barbieri%20et%20al.%2C%202015.
pdf



Pa
ge

 
6

https://journals.e-palli.com/home/index.php/ajec

Am. J. Environ. Clim. 4(2) 1-6, 2025

Buagas, D., Megraso, C., Namata, J., Lim, P., Gatus, K., 
& Canete, A. (2014). Tracking quicksilver: Estimation 
of  mercury waste from consumer products and 
subsequent verification by analysis of  soil, water, 
sediment, and plant samples from the Cebu City, 
Philippines, landfill. Environmental Monitoring and 
Assessment, 187(138). https://doi.org/10.1007/
s10661-014-3577-9

Chen, W., Zhu, K., Yankun, C., Yuelin, W., & Yingping, 
L. (2021). Distribution and ecological risk assessment 
of  arsenic and some trace elements in soil of  different 
land use types, Tianba Town, China. Environmental 
Technology & Innovation, 22, 102041. https://doi.
org/10.1016/j.eti.2021.102041

Chonokhuu, S., Batbold, C., Chuluunpruev, B., 
Battsengel, E., Dorjsuren, B., & Byambaa, B. (2019). 
Contamination and health risk assessment of  heavy 
metals in the soil of  major cities in Mongolia. 
International Journal of  Environmental Research and 
Public Health, 16(14), 2552. https://doi.org/10.3390/
ijerph16142552

Cortez, L., & Ching, J. (2014). Heavy metal concentration 
of  dumpsite soil and accumulation in Zea mays (corn) 
growing in a closed dumpsite in Manila, Philippines. 
International Journal of  Environmental Science and 
Development, 5(1), 77–80

Department of  Environmental and Natural Resources. 
(2019). DENR Administrative Order no. 2019-17: 
Chemical control order for arsenic and arsenic compounds. 
h t tps ://chemica l .emb.g ov.ph/w p-content/
uploads/2019/11/DAO201917Arsenic.pdf

Hakanson, L. (1980). An ecological risk index for aquatic 
pollution control: A sedimentological approach. Water 
Research, 14, 975–1001.

Horwell, C., Baxter, P., & Kamanyire, R. (2020). Health 
impacts of  volcanic eruption. In Volcanic health hazards 
(pp. 15–29). Cambridge University Press. https://doi.
org/10.1017/CBO9781316276273.015

Jenkins, S., Wilson, T., Magill, C., Miller, V., Blong, S., 
Marzocchi, W., & Boulton, M. (2015). Volcanic ash 
fall hazard and risks. In Volcanic health hazards (pp. 
5–15). Cambridge University Press. https://doi.
org/10.1017/CBO9781316276273.005

Kim, A., Kim, J., Ko, M., & Kim, K. (2010). Acid rain 
impact on phytoavailability of  heavy metals in soil. Geosystem 
Engineering, 13(4), 133–138.

Lou, W., Lu, Y., Wang, T., Hu, W., Jiao, W., Naile, J., Khim, 
J., & Giesy, J. (2010). Ecological risk assessment of  
arsenic and metals in sediments of  coastal areas of  
northern Bohai and Yellow Seas, China. AMBIO, 
39(5), 367–375.

Ma, Q., Han, L., Zhang, J., Zhang, Y., Lang, Q., Li, F., 
& Han, A. (2019). Environmental risk assessment of  
metals in the volcanic soil of  Changbai Mountain. 
International Journal of  Environmental Research and 

Public Health, 16(20), 3903. https://doi.org/10.3390/
ijerph16203903

Martinez, F., Mijares, M., & Galera, T. (2011). Assessment 
of  the water quality of  Mamba river of  Mts. Palay 
Palay/Mataas na Gulod, Southern Luzon, Philippines. 
Laguna Lake Development Authority. http://llda.gov.ph/
wp-content/uploads/dox/waterqualityrpt/rivers/
sb.pdf

Martinez-Villegas, M., Reniva, P., Sanico, L., Loza, 
A., Seda, R., Doloiras, D., & Pidlaoan, A. (2022). 
Perspectives on the 12 January 2020 Taal Volcano 
eruption: An analysis of  residents’ narrative accounts. 
Frontiers in Earth Science. https://doi.org/10.3389/
feart.2022.923224

Muller, G. (1969). Index of  geo-accumulation in sediments 
of  the Rhine River. GeoJournal, 2(2), 108–118.

Nolos, R., Agarin, C., Domino, M., Bonifacio, P., Chan, 
E., Mascarenas, D., & Senoro, D. (2022). Health risks 
due to metal concentration in soil and vegetables 
from the six municipalities of  the island province in 
the Philippines. International Journal of  Environmental 
Research and Public Health, 19(3), 1587. https://doi.
org/10.3390/ijerph19031587

Posadas, R., Salting, A., Yamas, J., & Patayon, E. (2022). 
Mercury concentration of  the soil profiles of  the 
abandoned mercury mine in Sta. Lourdes, Puerto 
Princesa City, Palawan, Philippines. Philippine Journal 
of  Science, 151(3), 895–899.

Radomirovic, M., Cirovic, Z., Maksin, D., Bakic, T., Lukic, 
J., Stankovic, S., & Onjia, A. (2020). Heavy metals in 
the soil at a former painting industry facility. Frontiers 
in Environmental Science, 8, 560415. https://doi.
org/10.3389/fenvs.2020.560415

Riaz, R., Murtaza, G., Farooqi, Z., Ali, S., Aziz, H., 
Mahboob, S., Al-Ghanim, K., Owens, G., Ahmad, 
H., & Riaz, U. (2022). Assessment of  arsenic 
contamination in groundwater and associated human 
health risk. Sustainability, 14(19), 12460. https://doi.
org/10.3390/su141912460

Sharma, H., Rawal, N., & Mathew, B. (2015). The 
characteristics, toxicity, and effects of  cadmium. 
International Journal of  Nanotechnology and Nanoscience, 3, 
1–9.

United States Environmental Protection Agency. (2001). 
Exposure and health effects. https://www.who.int/
water_sanitation_health/dwq/arsenicun3.pdf

World Health Organization. (2007). Natural disasters: 
Coping with the health impact. https://www.eird.org/
isdr-biblio/PDF/Natural%20disasters%20coping.
pdf

Wuana, R., & Okieimen, F. (2011). Heavy metals in 
contaminated soils: A review of  sources, chemistry, 
risks, and best available strategies for remediation. 
ISRN Environmental Chemistry, 2011, 402647. https://
doi.org/10.5402/2011/402647


