Content uploaded by Maria Victoria Ortega Espaldon
Author content
All content in this area was uploaded by Maria Victoria Ortega Espaldon on Sep 11, 2019
Content may be subject to copyright.
Content uploaded by Philippe Le Coustumer
Author content
All content in this area was uploaded by Philippe Le Coustumer on Mar 07, 2016
Content may be subject to copyright.
RESEARCH ARTICLE
Trends of labile trace metals in tropical urban water under highly
contrasted weather conditions
J. D. Villanueva
1,2,3
&P. Le Coustumer
1
&A. Denis
2
&R. Abuyan
4
&F. Hune a u
5,6
&
M. Motelica-Heino
7
&N. Peyraube
2
&H. Celle-Jeanton
8,9,10
&T. R. Perez
11
&
M. V. O. Espaldon
3
Received: 25 March 2015 /Accepted: 2 June 2015 /Published online: 18 June 2015
#Springer-Verlag Berlin Heidelberg 2015
Abstract The spatio-temporal trend of trace metals (Cd, Co,
Cr, Cu, Ni, Pb, and Zn) in a tropical urban estuary under the
influence ofmonsoon was determined using diffusive gradient
in thin films (DGT) in situ samplers. Three different climatic
periods were observed: period 1, dry with dredging activity;
period 2, intermediate meaning from dry to wet event; and
period 3, wet having continuous rainfall. Conforming to mon-
soon regimes, these periods correspond to the following: tran-
sition from winter to summer, winter, and summer monsoons,
respectively. The distinction of each period is defined by their
specific hydrological and physico-chemical conditions. Sub-
stantial concentrations of the trace metals were detected. The
distribution and trend of the trace metals under the challenge
of a tropical climate were able to follow using DGT as a
sensitive in situ sampler. In order to identify the differences
among periods, statistical analyses were performed. This
allowed discriminating period 2 (oxic water) as significantly
different compared to other periods. The spatio-temporal anal-
ysis was then applied in order to distinguish the trend of the
trace metals. Results showed that the trend of trace metals can
be described according to their response to (i) seasonal varia-
tions (Cd and Cr), (ii) spatio-temporal conditions (Co, Cu, Ni,
and Pb), and (iii) neither (i)nor(ii) meaning exhibiting no
response or having constant change (Zn). The correlation of
the trace metals and the physico-chemical parameters reveals
that Cd, Co, Cu, and Cr are proportional to the dissolved
oxygen (DO), Cd and Ni are correlated pH, and Zn lightly
influenced by salinity.
Keywords Labile trace metal .Urban water .Tropical
climate .Monsoon .Statistics .DGT
Environ Sci Pollut Res (2015) 22:13842–13857
DOI 10.1007/s11356-015-4835-6
Responsible editor: Philippe Garrigues
*P. Le Coustumer
plc@lnet.fr
1
Université de Bordeaux, Université Bordeaux Montaigne, EA 4592
Géoressources & Environnement, ENSEGID, 1 allée F. Daguin,
F-33607 Pessac, France
2
Université de Bordeaux, I2M-GCE, B18 Avenue des facultés,
33405 Talence, France
3
Los Baños, School of Science and Environmental Management,
College, University of the Philippines, Laguna 4031, Philippines
4
Mathematics Department, Southern Luzon State University, Lucban,
4328 Quezon, Philippines
5
Faculté des Sciences et Techniques, Laboratoire d’Hydrogéologie,
Université de Corse Pascal Paoli, Campus Grimaldi, BP 52,
F-20250 Corte, France
6
CNRS, UMR 6134, SPE, F-20250 Corte, France
7
Université d’Orléans, UMR CNRS 7327, ISTO, Campus
Géosciences, 1A rue de la Férollerie, F-45071 Orléans Cedex
2, France
8
Laboratoire Magmas et Volcans, Clermont Université, Université
Blaise Pascal, BP 10448, 63038 Clermont-Ferrand, France
9
CNRS, UMR 6524, LMV, 63038 Clermont-Ferrand, France
10
IRD, R 163, LMV, 63038 Clermont-Ferrand, France
11
Department of Environmental Science, Ateneo de Manila University,
Loyola Height, Quezon 1108, Philippines
Introduction
Tropical waters are dynamic environments. There are loads of
factors that influence these aqueous systems such as different
activities like estuarine mixing, tidal currents, sediment remo-
bilization, and fine grain sediments transport (Kuehl et al.
1996 and Breckel et al. 2005). Moreover, seasonal timescales
(e.g., monsoonal climate) induced by precipitation and other
weather conditions affect the hydrological cycle (Chakraborty
et al. 2010). Under monsoon regime, seasonal differences are
pronounced and mostly distinguished by the absence and
presence of precipitation (Takahashi 2013). This type of cli-
mate is challenging as uptight circumstances are at hand. Al-
terations in the hydro-climatic scheme can be experienced
(Hestir et al. 2013). For instance, incident of disruptions of
the ocean-atmosphere interactions can occur (Shirasago-Ger-
mán et al. 2015). These are principal sources of disturbance in
water basins.
Nowadays, the increasing apprehensions on the tropical
waters not only rest in the hydro-climatic conditions but also
on the water quality as well. Particular interests are on the
trace metals in terms of contamination and environmental
risks. These are important environmental issues. Studies aim
to know the possible effects of metals in urban runoff
(Herngren et al. 2005) and pollution discharges (Ki et al.
2011) in the aquatic system and the biota.
Trace metals are ubiquitous, easily transported to water
(Chen et al. 2014). The behavior of the trace metals in estuar-
ies varies greatly due to environmental factors like hydrody-
namic residence time, mixing patterns of transport processes,
and reservoir management (Hatje et al. 2003;Massonetal.
2006; Masson et al. 2011). Another factor is the water chem-
istry that changes from freshwater to saltwater that influences
their occurrence (Jiann and Wen 2009). The trend differs ac-
cording to seasonal changes and suspended sediments concen-
trations (Park et al. 2011). Precipitation, for example, can play
as an atmospheric wash out that delivers trace metals to aquat-
ic ecosystem through deposition mechanism (Özsoy and
Örnektekin 2009). To deduce, in tropical waters, trace metals
can be perceived as active components in the environment
and, at the same time, reactive elements in the aqueous sys-
tems. These directed toward serious intentions and efforts to
assess the water quality of tropical waters including estuaries
specially those who are situated in highly urbanized zones.
Labile trace metals are vital in examining the state of these
tropical waters. This fraction can eventually help in assessing
toxicity and associated risks (Pinheiro and Domingos 2005).
However, measuring these specific forms requires collecting
voluminous water which is tedious and time consuming
(Graveline et al. 2010). Alternatively, in situ sampling tech-
nique can be employed. It can provide data over longer pe-
riods of time and reduces some of the drawbacks of grab
sampling (INAP 2002).
For this reason, diffusive gradient in thin films (DGT) is
used to monitor trace metals in aquatic system. This device
has the ability to perform measurements (Davison and Zhang
1999) at a lower cost. It is an in situ method that can sequester
labile fractions (Naylor et al. 2004;Lietal.2005;Søndergaard
et al. 2008; Vystavna et al. 2012a,b) even at very low con-
centrations (Zhang et al. 1995). This technique for measuring
trace metal and monitoring water bodies is long-established
and delivers valuable results with lesser sampling activities
needed (Alfaro-De la Torre et al. 2000;Clarisseetal.2009;
Gao et al. 2010;Wuetal.2011; Villanueva et al. 2013).
The purpose of this research is mainly to determine the
labile trace metals response to differing climatic and
physico-chemical conditions in a dynamic estuarine system
in a tropical setting. The Pasig River in Manila, Philippines
was chosen due to the distinct water dynamics (as this is an
estuary in nature) and climate background. The seasonal
changes are pronounced and contrasting because of the influ-
ence of the monsoon and precipitation anomalies over tropical
regions (Villafuerte et al. 2014). These variations are caused
by surface reverse directions and local winds (Han et al.
2009).
This study would like establish the trend of labile trace
metals in a tropical water facing monsoon seasons. The focus
is on determining the importance of the episodic events on the
trace metal loads and availability of the labile fractions in
highly industrialized and urbanized tropical water. The specif-
ic objectives are (1) to describe the trend of the labile trace
metal (Cd, Co, Cr, Cu, Ni, Pb, and Zn), (2) to distinguish the
effect of seasonal changes under monsoon regime in a tropical
aquatic system in terms of hydrochemistry and physico-
chemical conditions, and (3) to determine which among labile
trace metals are more vulnerable to spatio-temporal changes.
Three local seasons were considered: dry, transition from
dry to wet (intermediate), and wet. The difference in the sea-
sonal pattern can lead to a premise that the trace metals trend
will also be significantly distinct from each period. To assess if
this premise holds, statistics were performed. Hydrochemistry
and physical conditions were utilized as parameters. Spatio-
temporal analysis was applied to better explain the labile trace
metal trends.
Materials and methods
Site description
The Pasig River is an estuary of about 27 km long and ap-
proximately 80 m wide. The catchment is composed of 4 main
tributaries (San Juan River, Marikina River, Napindan River,
and Pateros-Taguig River) and 43 minor tributaries. It is lo-
cated in the heart of Manila, Philippines (Fig. 1) and connects
Laguna Lake (east), the biggest freshwater lake in the
Environ Sci Pollut Res (2015) 22:13842–13857 13843
Philippines and the Manila Bay (west). The salinity intrusion
from the bay can reach toward the whole stretch of the Pasig
River to the mouth of the lake.
Manila Bay mostly serves as a shipyard. Laguna Lake
has many functions that include aquaculture and fishery
(open fishing), irrigation, power generation, and naviga-
tional lane. This site is situated in a highly industrialized
and urbanized area with a rough estimated population of
11,500,000 plus fluxes of informal settlers which are
about 30 % of the total Metro Manila region (Aiga and
Umenai 2002). This water body normally receives non
point sources of effluent wastes of different forms. Poor
solid waste management is in addition a challenge in the
area.
Sampling design
The sampling design followed seasonal patterns in the study
area. Sampling campaigns were conducted that corresponded
to period 1, dry with an ongoing dredging activity (April to
May 2010); period 2, intermediate: from dry to wet season
(January 2011); and period 3, wet season (May to June 2011).
The rainfall behavior during the sampling campaigns is pre-
sented in Table 1. Following these differing precipitation rates,
the hydrology of the Pasig catchment varied strongly in be-
tween periods.
Four sites (Fig. 1) were chosen representing the upstream
(point 1: mouth of the Manila Bay), midstream (points 2 and
3 which are near the San Juan and Marikina River, respec-
tively), and downstream (point 4: mouth of the Laguna
Lake), with an approximate distance of 7 km in each site.
Point 4 signals freshwater interference in the river. In each
site, DGT in duplicates were fully immersed for 18 days.
DGT field blank was provided per sampling campaign.
Strict protocols of DGT deployment (Villanueva 2013)
were followed for all sampling campaigns. Immediately,
after the retrieval, the DGT probes were rinsed with de-
ionized water and placed in pre-cleaned properly marked
resealable plastic containers. A cooling compartment was
prepared to transport the probes directly to the laboratory.
DGTs were put in the refrigerator before the extraction of
the trace metals.
During each sampling campaign, physical parameters such
as dissolved oxygen (DO), water temperature, salinity, con-
ductivity, and pH were measured in situ using YSI 6600 V2
data probe at a depth of approximately 1 m below the water
surface. The range of values is presented in Table 2.Accord-
ing to the study of Materum 2010 and Villanueva 2013,total
organic carbon (TOC) of the Pasig River ranged from 3.4 to
4.5 mg/L during May 2010 and 3.5 to 7.4 mg/L for January
2011.
Fig. 1 The PasigRiver map and sampling sites (point 1: moth of the ManilaBay; point 2: near the convergence of the San Juan River, point 3: near the
confluence of the Marikina River; and point 4: near the Laguna Lake)
Tabl e 1 Rainfall rate during the sampling campaigns
Rainfall (mm) Period 1 Period 2 Period 3
Days before sampling*
10 0.8 5.4 19.6
20 0.8 14.4 125.2
Accumulated within the
sampling period
67979.8
*Days before DGT installation
Provided by Manila Observatory (unpublished data 2012)
13844 Environ Sci Pollut Res (2015) 22:13842–13857
Determination of trace metals concentration
Standard solution Chelex-100 DGT probes were purchased
from DGT Research Ltd., Lancaster, UK. DGT field blanks
were extracted and analyzed using the same procedure for the
DGTs immersed in the water. Laboratory procedural blanks
were prepared. The detection limits were determined follow-
ing the already established procedure (Pettke et al. 2012). In
the laboratory, the membrane filter and the diffusive gel were
carefully removed from the piston using Teflon tweezers. The
gel was separated and placed into a clean polypropylene micro
centrifuge tube. One milliliter of 1 M of HNO
3
(Fisher Scien-
tific Analar grade) was added. After 24 h, dilution was per-
formed. The trace metals were determined using inductively
coupled plasma-mass spectrometry (Thermo
Scientific*ELEMENT2*ICP-MS). From the elution solution,
the accumulated mass of the trace metals then the concentra-
tions were calculated. The detailed laboratory procedures
(Dunn et al. 2007; Nyein Aung et al. 2008) and calculations
(DGT Research 2002) can be found elsewhere (INAP 2002).
Trend analysis approach
Two approaches were applied: statistical and spatio-temporal
analyses. The statistical analyses permit discriminating the
periodical differences. This can also describe the relationship
in between parameters: hydro- and physico-chemical vari-
ables and trace metal concentrations. The spatio-temporal
analysis is valuable in determining the trends of the trace
metals by evaluating their response in each seasonal or tem-
poral variation and inspecting the increase or decrease of the
concentration in a spatial sense.
Statistical tests
In order to determine the significance among periods using the
concentrations of the pool of labile metals, series of statistical
tests were utilized. Student ttest was considered as it is ap-
propriate for small data sets (population samples). This test is
normally applied for the comparison of two means (Fritz and
Berger 2015). Hence, allowing comparing a period to another
using the concentration of the trace metals as data sets. Two-
tailed ttest was employed pairing each period’sdatasets(trace
metals concentrations). The significance level was determined
using the value α=0.05. To validate and illustrate the differ-
ence, hierarchical cluster analysis was performed.
Correlation analysis was applied to determine the potential
relationship of the physico-chemical parameters (DO, water
temperature, pH, salinity, and conductivity) and how each can
influence one another. Subsequently, the correlation of the
physico-chemical parameters to the labile trace metals was
carried out.
Spatio-temporal analysis
The spatio-temporal analysis can discriminate the trend of
each labile trace metals by examining the tendency of concen-
trations. The variation can be sorted according to the inclina-
tion of each trace metal. This approach aids in determining
which trace metals are susceptible to (i) seasonal or climatic
conditions changes, (ii) spatial or local variations, (iii) both
spatial and seasonal disparities, and (iv) neither spatial nor
local situation (absence of changes). The first can be related
to temporal events, while the second can be associated to
anthropogenic activities and/or instantaneous contamination.
The last can be described as having a conservative or constant
trend.
Results
Environmental background and physico-chemical
parameters
The physico-chemical characteristics of the water were re-
corded during each sampling period (Table 2). Period 1 com-
bines two episodic events: dry season and dredging activity.
The area experienced shortage on rainfall. Periods 2 and 3, on
the other hand, both experienced pronounced rainfall
(∼79 mm). Period 2 showed the lowest record for water tem-
perature, salinity, and conductivity. This period has the highest
DO level. The periods were best described by the DO as the
oxygen levels greatly varied through periods. DO range from
0.45 to 1.05 mg/L on period 1, 5.9 to 8.2 mg/L on period 2,
and 1.55 to 2.26 mg/L on period 3. Only period 2 passed the
Department Administrative Order (DAO 34) of the Philippine
government. The DO requirement is >5 mg/L. The salinity
was pronounced on period 3 (0.39 to 8.44 psu) which also
indicated water mixing. In period 2, salinity was almost con-
stant along the Pasig River stretch. Compared to DO, salinity
and conductivity, pH did not exhibit strong variations.
Tabl e 2 Physico-chemical
parameters’range of values Period Water temperature (°C) DO (mg/L) pH Salinity Conductivity (ms/cm)
131 0.45–1.05 7.89–8.35 0.55–3.60 6.00–22.00
226–27 5.90–8.20 7.31–7.73 0.39–0.40 0.81–0.84
331–32 1.55–2.26 6.80–7.03 0.39–8.44 1.00–16.00
Environ Sci Pollut Res (2015) 22:13842–13857 13845
Fig. 2 DGT-labile trace metals’
concentrations (ng/L)
13846 Environ Sci Pollut Res (2015) 22:13842–13857
Labile trace metals in the Pasig River
The general trend observed was that most of labile trace
metals concentrations increased during period 2 then de-
creased during period 3 (Figs. 2and 3and Tables 3and 4).
However, throughout the period, Zn seemed stable. During
period 1, the only DGT-trace metals (at maximum) found at
the river end is Ni located near the mouth of the bay (point 1).
Minimum Ni was detected at the confluence of San Juan River
(point 2) while Co has the least at the mouth of the bay (point
1). Maximum concentrations weremostly near the confluence
of San Juan River (point 2: Cr, Cd, and Pb) and convergence
of Marikina River (point 3: Co, Cu, and Zn).
The minimum concentrations of Cr, Cu, Zn, Cd, and Pb
were found near the mouth of the lake area (point 4). In this
period, at the river ends (points 1 and 4), lower values of Cr,
Co, Cu, Cd, and Pb were found. In contrast, Ni has the lower
values in the midstream (points 2 and 3). Zn concentration
spatially varies. In period 2, minimum value of Pb is found
near the mouth of the bay (point 1); Cr, Cu, and Zn were at
the confluence of San Juan River (point 2); Co and Ni near
Marikina River area (point 3); and Cd near the mouth of the
lake (point 4). Maximum values of Cr, Cu, Zn, and Cd were
found near the mouth of the bay (point 1), while, Co, Ni, and Pb
at the mouth of the lake (point 4). At this period, the maximum
values are all found at the river ends (points 1 and 4).
For period 3, Cu has the least concentration at the mouth of
the bay (point 1). Maximum values were traced in the
sampling points except near the lake: Cr and Cd were found
near the bay area; at the confluence of San Juan River (point 2:
Co, Zn, and Pb) and near at the Marikina River (point 3: Ni
and Cu). Most of the minimum values were at the mouth of the
lake (point 4: Cr, Co, Ni, Zn, Cd, and Pb).
Labile trace metal concentrations and statistical difference
among periods
The Student ttest was performed by pairing the data (period 1
vs. period 2; period 1 vs. period 3; and period 2 vs. period 3).
The result ofthe statisticaltest is shown in Table 5. Significant
difference were found in between periods 1 and 2 (α=0.05;
p=0.022) and periods 2 and 3 (α=0.05; p=0.016) but not for
period 1 and period 3 (α=0.05; p=0.437).
To illustrate, the hierarchical cluster analysis was per-
formed generating a dendrogram (Fig. 4a). The dissimilarity
between the periods agreed to the statistical analysis per-
formed where period 2 was isolated (left). Observations on
the spatial patterns of periods 1 and 3 showed that for both
periods, most of the maximum concentrations of each trace
element are found at the midstream (points 2 or 3), while most
of the minimum concentrations of each trace element are at the
endstream (points 1 or 4). Another dendrogram (Fig. 4b)was
generated considering only periods 1 and 3. The result dem-
onstrated that period 1 is grouped together, whereas period 3 is
clustered into three groups.
Fig. 3 Spatio-temporal variation of the trace metals among period
Environ Sci Pollut Res (2015) 22:13842–13857 13847
Correlation among parameters
The correlation among physico-chemical parametersis shown
in Table 6. DO has an inverse relationship to other physico-
chemical parameters. This inverse relationship is more pro-
nounced with respect to the water temperature (α=0.05; p=
−0.91). In terms of salinity, periods 1 and 3 showed evident
water mixing. Although, the salinity values are lower in period
1, water mixing was also observed. There is also a weak con-
firmation of the inverse relationship of DO to salinity (α=
0.05; p=−0.42). Water temperature and salinity are positively
correlated to conductivity, whereas DO showed negative
correlation.
Among trace metals (Table 7), Zn demonstrated weak cor-
relation to other trace metals. Direct relationship was present
in between the following trace metals: Co-Cd (r=0.80),Co-Cr
(r=0.77), Cu-Cd (r=0.71), Cu-Co (r=0.69), Cu-Cr (r=0.92),
and Ni-Cd (r= 0.75). In between the physico-chemical param-
eters and the trace metals, DO followed the Cd, Co, Cu, and
Cr, and pH is correlated to Cd and Ni. Potential relationship in
between salinity and Zn was traced.
Discussion
Environmental background
The Philippines is within the regime of monsoon seasons of
Southeast Asia (Loo et al. 2014). This type of climate system
is dynamic as it is characterized by wet spell having periodic
heavy rains and dry spell with seasonal changes driven by the
wind directions (Stephens et al. 2008). The active factors com-
ing from the interaction of the oceans and atmosphere could
lead to droughts and wet episodes (Buckleyet al. 2014). It has
significant impacts on the environment including water sys-
tems (Cook and Jones 2012; Varis et al. 2012). Monsoon
climate dictates the variability of the temperature of the water
catchments (Meybeck 2009) and hydrodynamics (Fuchs et al.
2012). It can also affect the quality of the water resource
(Wilkerson et al. 2002;Hestiretal.2013). For these reasons,
under this climate regime, it is noteworthy to know how the
hydrochemistry of the Pasig River responds.
Monsoonal Climate Regime
Seasonality of monsoon can be categorized according to
months. Cruz et al. 2012 explains that the main monsoon
regimes are the Northeast monsoon and the Southwest mon-
soon. Northeast monsoon or the winter monsoon can be ex-
pected on November to March. Southwest monsoon or sum-
mer monsoon starts May and ends on September. On October,
Tabl e 3 Concentration range of
detected labile trace metals in the
Pasig River (ng/L)
Trace
metals
Concentration ranges RSD Detection
limit
Period 1 Period 2 Period 3 Period 1 Period 2 Period 3
Cd 87–94 141–146 0.9–1.8 1.75 1.04 0.19 0.21
Co 28–82 119–277 62–100 11.24 34.27 9.09 6.44
Cr 205–236 6841–7632 13–23 6.82 184.50 2.15 10.86
Cu 88–314 506–867 149–251 48.93 82.92 23.17 7.63
Ni 154–434 206–255 22–27 61.33 12.57 1.09 2.94
Pb 95–122 50–643 7–16 6.95 131.25 2.18 1.21
Zn 827–1027 793–1236 431–1468 42.34 103.60 232.11 100.00
Tabl e 4 Anthropogenic activities surrounding the Pasig River and the
major trace metals concern
Site Important activities Major metals concern
Site 1 Shipyard Ni
Ceramic factory Co, Cr ,Pb
Electric company Cu
Textile and clothing Cr, Zn
Thermal power plant Cd, Ni, Pb, Zn
Food company Pb, Cu
Gasoline stations Cd, Co, Cr, Cu, Ni, Pb, Zn
Oil refinery Cd, Cr, Pb
Navigational lane Cd, Co, Cr, Cu, Ni, Pb, Zn
Site 2 Oil refinery Cd, Cr, Pb
Steel Cr
Oil and petroleum company Cd, Co, Pb, Zn
Woo d Cu
Electricity (electrical industry) Cu
Cigarettes Cd
Metal castings Co, Cr, Ni, Zn
Agroindustry Cd, Cu, Pb
Steels Cr, Ni
Site 3 Navigational lane Cd, Co, Cr, Cu, Ni, Pb, Zn
Aquaculture Cd, Co, Cr, Cu, Ni, Pb, Zn
Site 4 Fishing, irrigation Cd, Zn
Power generation Cd, Pb
Navigational lane Cd, Co, Cr, Cu, Ni, Pb, Zn
13848 Environ Sci Pollut Res (2015) 22:13842–13857
the transition from Southwest monsoon to Northeast monsoon
occurs. Adhering to the monsoon regime, period 1 fell under
the transition from Northeast to Southwest monsoon (in be-
tween winter and summer monsoon); period 2 experienced
Northeast/winter monsoon; and period 3 encountered
Southwest/summer monsoon.
Hydro-physico-chemical variation
The variation of DO followed by the water mixing express the
differences among periods. Through periods there is a shift
from almost anoxic to oxic then hypoxic waters. In terms of
incidence of water mixing, the trend is as follows: Period 3>
Period 1>Period 2. The conductivity follows the trend of the
salinity, Period 2 havingleast values. The water temperature is
almost the same for Periods 1; and 3 and lowest during Period
2. For pH, Period 1 was more basic than Period 2 and Period 3
played slightly acid to neutral water.
Spatio-temporal analysis on trace metals
Period 1 as stated was under a dry weather. Twenty days prior
to the sampling campaign, there was only 0.8 mm of rainfall.
A total of 6 mm of rainfall was accumulated within this sam-
pling period which implied river low flow. At this period,
there was an ongoing dredging activity. Dredging is an eco-
logical disturbance that can affect the sediment structure
(Mackie et al. 2007;Jeetal.2007). Both particulate forms
(Nayar et al. 2004) and bioavailability (Lewis et al. 2001)of
trace metals in the water column could increase (Cabrita 2014)
due to resuspension (Fathollahzade et al. 2015). Studies
showed that the release of the dissolved trace metals can be
attributed to the binding mechanism to the solid phase or on
the mechanisms involving sorptive phases (van den Berg etal.
2001). Also the changes in the water chemistry like pH and
ionic strength can affect the release of the dissolved trace
metals (i.e., lower pH increase the solubility of the trace
metals).
In wet seasons, atmospheric deposition, surface runoff
(Wittetal.2010), and atmospheric precipitation
(Migliavacca et al. 2005;VuaiandTokuyama2011)contrib-
ute to trace metals delivered to the receiving body (Dunn et al.
2007) such as rivers (Nyein Aung et al. 2008). Periods 2 and 3
both received almost the same amount of precipitation
throughout the sampling campaign. However, 20 days before
the sampling activity in period 3, the accumulated rainfall
amount was only 125.2 mm already, whereas period 2 re-
ceived only 14.4 mm. These periods displayed different
hydro-chemical characteristics. The hydro-chemical condition
illustrates the distinction of this period being least in salinity,
water temperature, and conductivity at the same time highest
in DO values. Period 3 has the highest recorded water temper-
ature, salinity, and conductivity. Knowing the hydro-chemical
background, the interesting issue is on what can be the re-
sponse of each of these differing conditions to the labile trace
metal concentrations.
Trace metal variation
The ranges of the trace metal concentrations are summa-
rized in Table 3, while the variations are presented in
Fig. 2. Period 2 is discriminated as significantly different
toperiods1and3.InTable4, the anthropogenic activities
surrounding the river with the trace metals concern are iden-
tified. To illustrate the distribution of the different labile
trace metals per period and site, pie charts were drawn in
Fig. 3. These pie charts represent relative percentage of the
concentrations of trace metals. Zn has the largest portion
during periods 1 and 3. In period 2, Cr has the leading share.
The second biggest part among periods is as follows: period
1: mostly Cd followed by Cr; period 2: Zn followed by Cu;
andperiod3:CuthenCo.
Tabl e 5 Student ttest result Groups tdf Sig.
(two-tailed)
Mean
difference
Std. error
difference
Period Dry (1) vs.
intermediate (2)
°° −2.43 27.77 0.022* −1109.41 455.75
Dry (1) vs.
Wet ( 3)
° 0.78 54.00 0.437 69.74 89.09
Intermediate (2) vs.
wet (3)
°° 2.57 28.32 0.016* 1179.15 458.05
*For 5 % level of significance, there isdifference on the mean response of dry vs. intermediate, and intermediate
vs. wet as showed in the pvalues (sig.<0.05)
° Equal variances assumed; °° equal variances not assumed
Environ Sci Pollut Res (2015) 22:13842–13857 13849
Fig. 4 Generated dendrogram.
Numbers indicate sampling
regime (Period) and points. aall
The periods and bperiods 1 and 3
(legend is provided in the middle)
Tabl e 6 Correlation (r)among
physico-chemical parameters Salinity Dissolved oxygen Water temp pH Conductivity
Salinity 1.00
Dissolved oxygen −0.42 1.00
Water Temp 0.36 −0.92 1.00
pH −0.40 −0.25 0.09 1.00
Conductivity 0.69 −0.70 0.52 0.26 1.00
13850 Environ Sci Pollut Res (2015) 22:13842–13857
Spatio-temporal variation of trace metals
As a point of observation, the variation of each trace metals
follows three trends. The trace metals can be grouped accord-
ing to their response in a spatio-temporal approach. First, the
trace metals that exhibited seasonal (temporal) variation or
changes of the concentrations differ between periods. Second,
trace metals that are sensitive spatially and temporally, indi-
cating variations in each site and in each period (season).
Third, a trace metal that is constant through time. Seasonal
variation is observed in labile trace metals Cd and Cr. The
spatial and temporal sensitive trace metals are depicted by
Co and Cu and mainly by Ni and Pb. Among the trace metals,
Zn has a different trend by appearing constant through time.
Cr and Zn: the trend and origin
Significant concentrations of trace metals were detected in the
Pasig River in varying amount. There is an interesting aspect
in terms of anthropogenic and geogenic origins. In Fig. 3,the
largest portions are Cr and Zn. Among the trace metals, Cr
showed the most considerable trend in between periods. The
results showed how the dissolved Cr in the Pasig River is
sensitive to seasonal and hydrochemistry changes. There is a
notable point in Cr being the highest during period 2. Table 4
provided probable sources of emissions situated at the river-
bank. Cr could also be associated to atmospheric fallout or
rainfall and surface runoffs (Neal et al. 1996). During period
3, a series of rainfall served as a wash out of Cr that is why
lesser concentration was detected.
As the spatio-temporal analysis revealed, unlike Cr, Zn is
neither affected by dilution nor the variation of physico-
chemical parameters. Zn is normally abundant in urban water
runoff. It is interesting to look at its geogenic origin. The
interaction of Zn with Cd and the distribution in estuaries
can be studied (Audry et al. 2004; Dudka et al. 1994).
The fractionation of Zn/Cd can explain the trace element
pattern as a response to the geochemical phases. Its concen-
tration ratio changes according to different geochemical
phases occurring in geochemical path such as in streams, riv-
ers, estuaries, coastal seas, and open oceans (Gerringa et al.
2001). The result of this study showedthat Zn has a significant
relationship to Cd (r=0.61). Zn/Cd ratio can give clear esti-
mates on the relative geochemical behavior (Mazeina et al.
1999) and can trace their sources. The Zn/Cd ratio obtained
ranges 9.32–11.65 for period 1; 5.88–8.48 for period 2; and
502.72–1174.83 for period 3. The ratio that ranges from 5–10
can be attributed for oceanic waters (Gerringa et al. 2001). In
the world record, the ratio 7.5 is said to be carried by riverine
suspended sediments to the oceans in dissolved phase (Viers
et al. 2009). Higher ratio (>500), like in period 3, can be traced
in ore elements from basaltic, igneous rocks, and sediments
(Gerringa et al. 2001; Nolting et al. 1999;Gottesmannand
Kampe 2007). Thus, there is an indication that most of Zn
came from runoff.
Importance of the physico-chemical parameters
on the labile trace metals
Physico-chemical environmental parameters are very essential
in explaining the chemical spatial distribution of the trace
metals. DO plays an important role which is highly influenced
by seasonal changes (Sokolowski et al. 2001). As a main
point, DO give inverse relationship to other physico-
chemical parameters. This inverse relationship is more distinct
with respect to the water temperature followed by conductiv-
ity. There is a weak proportional relationship in between DO
and salinity. Although, the results confirmed the direct rela-
tionship in between conductivity and salinity, two tendencies
were noticed. Period 1 showed higher slopes than period 3.
Although salinity is lesser in period 1, conductivity is higher.
pH displayed weak inverse correlation to salinity and
conductivity.
Positive correlations (r>0.60) in between most of the trace
metals were observed. Weak correlations (r<0.50) are found
in between Cd-Co, Ni-Co-, Ni-Cr, and Ni-Cu. Zn portrayed no
correlation with other trace metals. The relationships of the
concentrations of physico-chemical parameters and labile
trace metals among periods are presented in Fig. 5and
Table 7.
DO Pasig River showed that trace metals (Cd, Co, Cr, Cu, and
Pb) are directly proportional to DO except for Ni and Zn. Oxic
water favors dissolved metals (Buffle and van Leeuwen
1993). The oxic levels of each period are distinguished ac-
cordingly: period 1 is near anoxia, period 2 shows oxic water,
and period 3 is hypoxic water (Table 2). Using the
Table 7 Correlation (r): among labile trace metals and labile trace
metals to the physico-chemical parameters
Cd Co Cr Cu Ni Pb Zn
Cd 1.00
Co 0.48 1.00
Cr 0.80 0.77 1.00
Cu 0.71 0.69 0.92 1.00
Ni 0.75 0.12 0.38 0.28 1.00
Pb 0.68 0.71 0.69 0.47 0.40 1.00
Zn −0.04 0.06 0.06 0.16 −0.12 −0.14 1.00
pH 0.52 −0.25 −0.06 −0.04 0.75 0.08 −0.13
Salinity −0.59 −0.28 −0.48 −0.48 −0.52 −0.41 0.53
DO 0.65 0.88 0.95 0.84 0.24 0.76 −0.02
Wat er tem p −0.78 −0.77 −0.98 −0.91 −0.28 −0.67 −0.18
Conductivity −0.29 −0.60 −0.63 −0.63 −0.12 −0.38 0.25
Environ Sci Pollut Res (2015) 22:13842–13857 13851
abovementioned parameters and their relationships to the dis-
solved oxygen, period 2 should have the highest trace metal
concentration followed by period 3. Period 1 will give the
least concentrations. This is true for the actual case of period
2 only but not for periods 1 and 3. During period 3, continuous
rainfall led to lesser concentrations of the trace metals. Figure 5
shows that fromhypoxic toward oxic level, the concentrations
of most of the trace metals (Cd, Co, Cr, Cu, Ni, and Pb)
increased. In oxic water, trace metals are mostly driven by
sorption reaction while trace metals are controlled by sulfide
precipitation in anoxic water (Buffle and van Leeuwen 1992).
Sulfides are strong reducing agents. Low concentration of
trace metals in the anoxic water is due to metal sulfide precip-
itation (Zwolsman and Van Eck 1993).
pH Water pH influences the evolution of the concentration of
Cd and Ni. The pH of the Pasig River is as follows: period 1,
alkaline water; period 2 ∼neutral water; and period 3, near
acidic and neutral water. Following the trace metal and pH
relationship, period 1 should have the highest concentration
while period 3 the least. This is true for the case for period 3.
However, period 1 ranked the second in terms of labile trace
metal concentration even if the water is alkaline. Period 2 is in
the first order because of sorption. In Fig. 5, it presents that the
concentrations of the trace metals are lower at pH ∼7thenthere
is increase of concentrations after the neutral level until ph∼
7.5. The trace metals distribution is affected by the pH through
acid-base reaction (vanLoon W and Duffy 2000). Trace metals
sorption has proportional relationship with increasing pH
(Munk et al. 2002). The adsorption of metal cations are more
likely to happen when pH increases at the water column, as the
latter increases the particle surface negative charge
(Gurumurthy et al. 2013). This can also mean that desorption
can be experienced predominantly in the acidic water. Water at
high pH promotes insolubility of the trace metals.
Salinity and conductivity Most of the dissolved trace metals
in periods 1 and 3 have the least concentration near the lake.
Fig. 5 Relationship of the physico-chemical parameters to the labile trace metal concentrations
13852 Environ Sci Pollut Res (2015) 22:13842–13857
These periods showed decreasing salinity and conductivity
from the bay to the lake. Flocculation of trace metals can be
experienced in the area where the lowest salinity was found
(Gerringa et al. 2001; Biati et al. 2010). This observation
explains why least trace metal concentrations were found dur-
ing this period at the mouth of Laguna Lake (except for Cu
and Pb, r=0.47). Zn has consistent trend having the least
concentration near the bay. Zn is mainly influenced by salinity
(Boughriet et al. 1992). In this study, a probable relationship
between Zn and salinity is observed (r=0.53). Like salinity,
most of the trace elements have inverse proportion to conduc-
tivity. Negative correlations are mostly found for Co, Cr, and
Cu.
Water quality threshold
The Pasig River is a highly urbanized water resource. Several
industries and companies surround this river. Table 4shows
potential industrial sources of metals. The Philippines would
like to comply with the United Nation’sAGENDA21onthe
protection ofthe quality, supply, and potential source of water.
In the past, Pasig River is an important water source for do-
mestic consumptions of the local inhabitants. Progressively,
water quality degradation sank in, manifested by high turbid-
ity and foul smell. Rehabilitation programs are in place to
bring back Pasig River to its previous state. Therefore, the
concern on the state of the water quality is important.
If the occurrence of the trace metals in drinking water set by
the World Health Organization (WHO 2008) will be followed,
the following trace metals exceeded the value; Cr of period 2
which is above 2 μg/L; Cu which is above the minimum value
of 0.005 μg/L; and Ni which is above 0.02 μg/L. Cd and Pb is
less than the normal occurrence in drinking water (<1 and
<5 μg/L, respectively). The Zn occurrence in the freshwater
exceeded the WHO consideration as it is more than the range
of 0.01–0.5 μg/L. Co is less than the norm. The Canadian
Environmental Protection Act, 1999 of the Federal Environ-
mental Quality Guidelines stated that worldwide, Co
concentrations is less than 1 μg/L in surface freshwater and
0.3–1.7 μg/L in rainwater. This insinuates that the trace metal
concentrations measured in the Pasig River are not negligible.
Comparison of results to other DGT studies
The measured concentrations in this study are compared to
other studies that employed DGT in estuaries and coastal wa-
ters influenced by anthropogenic activities. For instance, there
is an interesting study in the Basque-French estuaries
(Montero et al. 2012) situated in an industrial and mining area.
The measured concentrations in the Pasig River during pe-
riods 1 and 2 are within the range of the values obtained in
this study: Cd (2–1570 ng/L) and Ni (30–3650 ng/L). For Cu
(66–515 ng/L), the Pasig River has wider range and higher
value. The coastal sites of Sardinia in Italy (Schintu et al.
2010) located in a mining and lead-zinc smelting area showed
higher Cu concentration range (1.45–2.23 μg/L). The mini-
mum value of Cd concentration in this site is the maximum
value obtained in the Pasig River (0.9 μg/L). Patos Lagoon in
Brazil (Costa and Wallner-Kersanach 2013), serves as marina,
port, and shipyard, has lower Cu concentration (0.11–
0.45 μg/L) than the Pasig River. Zn maximum concentration
of the Pasig River is the minimum value in this site (0.8 μg/L).
Baijao site of the Jiulong River in China is characterized as a
highly multi-metal contaminated estuary (Weng and Wang
2014). Pasig River has higher Cd, Cr, and Pb concentration
and wider range compared to this river. Jiulong River has
ranges of 0.04–0.12, 1.59–7.72, 0.05–0.39 μg/L, respectively.
The Co concentration of the Pasig River is within the range of
the Jiulong River (0.15–0.95 μg/L). The study in the Tama
River of Japan considered contrasted weather condition
(Nyein Aung et al. 2008). In this study, Cu was not detected.
Compared to the Pasig River, Tama River Ni, Pb, and Zn
concentrations (72 h deployment: 0.8, 0.39, and 3.6 μg/L,
respectively) have higher value than the Pasig River.
As a whole, measured concentrations in the Pasig River
correspond to the results of the studies that have shown
Tabl e 8 Detected sites which have highest and lowest labile trace metal concentrations
Trace metals Site of highest concentration Site of lowest concentration
Period 1 Period 2 Period 3 Period 1 Period 2 Period 3
Cd 211444
Co 342134
Cr 211424
Cu 313421
Ni 443234
Pb 242414
Zn 332424
Site 1: near Manila Bay; Sites 2 and 3: midstream; Site 4: near Laguna Lake
Environ Sci Pollut Res (2015) 22:13842–13857 13853
evident contamination. Although these past studies are rele-
vant, comparing is not easy. True enough that these sites are
similar aquatic systems and DGTs were utilized; however, the
conditions were not the same. Case in point is the duration of
DGT deployment. DGT samplers in this study were immersed
for more than 2 weeks, whereas most of the studies are done in
shorter periods: Basque-French estuaries: 10 days; Patos La-
goon, Brazil: 72 h; Sardinia, Italy: 3 days; Tama River, Japan:
46, 48, and 72 h; and Jiulong River estuary, China: 48 to 72 h.
Besides, not all considered highly seasonal contrasted condi-
tions. Another important issue is that dredging activity was
not a component of the reported studies.
Implication on water resources management
Labile trace metals are composed of inorganic and weak com-
plexes species (Gourlay-Francé et al. 2011). These species can
dissociate and/or has tendency for chemical changes. Serious
ecological concerns are arising as these can be dangerous for
the microorganisms like phytoplanktons (Baeyens et al. 2011)
at a high concentration (Sigg 2014). Hence, it is recommended
to measure the labile trace metals to better assess the water
quality of the surface water.
The highest trace metal concentration varies according to
season (Table 8). Spatial analysis indicates sources of the la-
bile trace metals. For instance, Cd and Cr were highest near
the bay area (site 2 during period 1 and site 1 for periods 2 and
3) and Ni was highest close to the lake (site 4 for periods 1 and
2 and site 2 for period 3). In terms of the lowest concentra-
tions, Cd has lowest value always near the mouth of the lake.
In this area also during period 3, least concentrations (Cd, Co,
Cr, Ni, Pb, and Zn) were observed.
The Pasig River is in continuous water quality surveil-
lance. The results provide information that trace metal con-
tributes mostly to the natural water system (e.g., Cr and Zn)
and needs more monitoring. From this study, water quality
measurements can be done according to the susceptibility of
the labile trace metals to the spatio-temporal trend. This can
give an idea in determining the frequency of sampling cam-
paigns. Labile trace metals that demonstrated spatio-
temporal variation (i.e., Co, Cu, Ni, and Pb) need more
sampling frequency. These are more exposed to changes in
terms of concentration. Those who are sensitive to seasonal/
temporal changes (i.e., Cd and Cr) can entail for lesser sam-
pling campaigns. This is as the former are more vulnerable
to labile trace metal contributors or sources. While, the one
that exhibited constant change (Zn) does not require high
sampling frequency. This means that the order of sampling
frequency is as follows: spatio-temporally inclined>
seasonally/temporally sensitive>unvarying or constant.
These recommendations hold unless unanticipated instanta-
neous contamination is present (e.g., oil leaks).
Conclusion
The study determined the labile trace metals trend in tropical
water (estuarine) under episodic event and differing climatic
conditions(period 1: dry and simultaneous dredging; period 2:
intermediate or in between dry and wet; period 3: wet). If the
monsoon regime will be followed, period 1 was under the
transition of winter to summer monsoon, period 2 was in an
event of winter monsoon, and period 3 encountered summer
monsoon.
The periods imply also different physico and hydro-
chemical characteristics. This discriminates the trend of trace
metals. Considerable amount of trace metals were detected
that can be a point of environmental concern especially during
period 2. The general trend found in trace metal concentra-
tions is as follows: period 2 present the higher one followed by
the period 1 and period 3 having the lowest concentrations.
The trend presented correlations in between the trace metals
and physico-chemical parameters. The statistical tests showed
that only period 2 is significantly different from periods 1 and
3.
The sensitivity of DGT as an in situ water sampler is
established. This is as DGTs were able to follow the trend of
the trace metals under contrasted climate conditions and epi-
sodic event.Evaluation based from the water quality threshold
and other DGT studies proves that substantial trace metals
contamination is present in the Pasig River. Furthermore, from
the results, (1) highest trace metals that contribute to the Pasig
River were determined (Cr and Zn); (2) three trends of trace
metals were identified, such as (i) spatio-temporally inclined,
(ii) seasonally or temporally sensitive, and (iii) constant or
unvarying;and (3) can latter facilitate in deciding the frequen-
cy of sampling or monitoring. The precedence is of this order:
spatio-temporally inclined (i.e., Co, Cu, Ni, and Pb)>season-
ally/temporally sensitive (i.e., Cd and Cr)>unvarying or con-
stant (i.e., Zn).
This study provides sound baseline information on the state
of the water quality and its response to seasonal changes and
environmental disturbance. It proves that the Pasig River is
susceptible to these changes and disturbance as depicted by
the variation of the values obtained from physico-chemical
parameters and labile trace metal concentrations. Furthermore,
major results presented that on the one hand, intermediate
season (from dry to wet) can bring higher concentration of
trace metals than the environmental disturbance (dredging).
On the other hand, continues rainfallcan cause washing effect
through dilution (as the concentration of the labile trace metals
notably diminished except for Zn).
Acknowledgments This research was funded by the Lyonnaise des
Eaux Company, Bordeaux, France and was done with the help of the
Pasig River Rehabilitation Commission (PRRC), LCDR Christopher
Meniado of the Philippine Coast Guards (PCG) and his staff, the
13854 Environ Sci Pollut Res (2015) 22:13842–13857
Department of Natural Resources and Environment-Environmental Man-
agement Bureau (DENR-EMB), and Dr. Gemma Narisma, Genie
Lorenzo, and James Simpas of the Manila Observatory. The authors are
also grateful to the French Embassy in the Philippines for giving financial
assistance for field mobility, the European Union ERASMUS MUNDUS
External Cooperation Window (ECW) Lot 12/13, and the Bourse Eiffel
Excellence (Programme 2012-2013) from the French Ministry of Foreign
Affairs for providing the academic grant and to Prof. Jorg Schäfer, Dr.
Farah Homsi, and Mr. Patrick Sin for all their technical inputs and support
and M. Jean Bernard Delmas for his encouragements.
References
Aiga H, Umenai T (2002) Impact of improvement of water supply on
household economy in a squatter area of Manila. Soc Sci Med 55:
627–641. doi:10.1007/BF02932265,PMCID: PMC2723519
Alfaro-De la Torre MC, Beaulieu PY, Tessier A (2000) In situ measure-
ment of trace metals in lakewater using the dialysis and DGT tech-
niques. Anal Chim Act 418:53–68. doi:10.1016/S0003-2670(00)
00946-6
Audry S, Jörg S, Blanc G, Bossy C, Lavaux G (2004) Anthropogenic
components of heavy metal (Cd, Zn, Cu, Pb) budgets in the Lot-
Garonne fluvial system (France). Appl Geochem 19:769–786. doi:
10.1016/j.apgeochem.2003.10.002
Baeyens W, Bowie AR, Buesseler K, Elskens M, Gao Y, Lamborg C,
Leermakers M, Remenyi T, Zhang H (2011) Size-fractionated labile
trace elements in the Northwest Pacific and Southern Oceans. Mar
Chem 126:108–113. doi:10.1016/j.marchem.2011.04.004
Biati A, Karbassi AR, Hassani AH, Monavari SM, Moattar F (2010) Role
of metal species in flocculation rate during estuarine mixing. Int J
SciTechnol 2:327–336. doi:10.1007/BF03326142,ISSN: 1735-
1742
Boughriet A, Oudane B, Fisher JC, Wartel FM, Leman G (1992)
Variability of dissolved Mn and Zn in the Seine Estuary and chem-
ical speciation of these metals in suspended matter. Wat Res 26:10,
1359–1378. doi:10.1016/0043-1354(92)90130-V
Breckel EJ, Emerson S, Balistrieri LS (2005) Authigenesis of trace metals
in energetic tropical shelf environments. Cont Shelf Res 25:1321–
1337. doi:10.1016/j.csr.2005.02.001
Buckley BM, Fletcher R, Wang S-Y S, Zottoli B, Pottier C (2014)
Monsoon extremes and society over the past millennium on main-
land Southeast Asia. Quat Sci Rev 95:1–19. doi:10.1016/j.
quascirev.2014.04.022
Buffle J, van Leeuwen HP (1992) Environmental Particles.
Environmental and physical chemistry series.Volume 1, Lewis
Publishers, Inc.
Buffle J, van Leeuwen HP (1993) Environmental Particles.
Environmental Analytical and Physical Chemistry Ser. CRC Press
ISBN-13.9780873718950
Cabrita MT (2014) Phytoplankton community indicators of changes as-
sociated with dredging in the Tagus estuary (Portugal). Environ
Pollut 191:17–24. doi:10.1016/j.envpol.2014.04.001
Chakraborty P, Babu PVR, Acharyya T, Bandyopadhyay D (2010) Stress
and toxicity of biologically important transition metals (Co, Ni, Cu
and Zn) on phytoplankton in a tropical freshwater system: An in-
vestigation with pigments analysis by HPLC. Chemosphere 80:
548–553. doi:10.1016/j.chemosphere.2010.04.039
Chen J, Zhang R, Wang H, Li J, Hong M, Li X (2014) Decadal modes of
seas surface salinity and the water cycle in the tropical Pacific
Ocean: The anomalous late 1990. Deep-Sea Res PT I 84:38–49.
doi:10.1016/j.dsr.2013.10.005
Clarisse O, Foucher D, Hintelmann H (2009) Methylmercury speciation
in the dissolved phase of a stratified lake using the diffusive gradient
in thin film technique. Environ Pollut 157:987–993. doi:10.1016/j.
envpol.2008.10.012
Cook CG, Jones RT (2012) Paleoclimatic dynamics in continental
Southeast Asia over the last ∼30,000 Cal yrs BP. Palaeogeogr
Palaeoclimatol Palaeoecol 339–341:1–11. doi:10.1016/j.palaeo.
2012.03.025
Costa LD, Wallner-Kersanach M (2013) Assessment of the labile frac-
tions of copper and zinc in marinas and port areas in Southern Brazil.
Environ Assess 185:6767–6781. doi:10.1007/s10661-013-3063-0
Cruz FT, Narisma TG, Villafuerte MQ II, Cheng-Chua KU, Olaguera LM
(2012) A climatological analysis of the southwest monsoon rainfall
in the Philippines. Atmos Res 122:609–616. doi:10.1016/j.
atmosres.2012.06.010
Davison W, Zhang H (1999) Diffusional characteristics of hydrogel used
in DGT and DET techniques. Anal Chim Acta 398:329–340. doi:10.
1007/s10661-013-3063-0
Dudka S, Piotrowska M, Chlopecka A (1994) Effect of elevated concen-
trations of Cd and Zn in soil on spring wheat yield and the metal
contents of the plants. Water Air Soil Pollut 76:333–341. doi:10.
1007/BF00482710
Dunn RJK, Teasdale PR, Warnken J, Jordan MA, Arthur JM (2007)
Evaluation of the in situ, time-integrated DGT technique by moni-
toring changes in heavy metal concentrations in estuarine waters.
Environ Pollut 148:213–220. doi:10.1016/j.envpol.2006.10.027
Fathollahzade H, Kaczala F, Bhatnagar A, Hogland W (2015)
Significance of environmental dredging on metal mobility from con-
taminated sediments in the Oskarshamn Harbor, Sweden.
Chemosphere 119:445–451. doi:10.1016/j.chemosphere.2014.07.
008
Fritz M, Berger PD (2015) Comparing two designs (or anything else!)
usingpairedsampleT-Tests.Improving the User Experience
Through Practical Data Analytics. Chapter 3 :71-89. doi 10.1016/
B978-0-12-800635-1.00003-3
Fuchs R, Dupouy C, Douillet P, Caillaud M, Mangin A, Pinazo C (2012)
Modelling the impact of a La Niña event on a South West Pacific
Lagoon. Marine Poll Bull 64:1596–1613. doi:10.1016/j.marpolbul.
2012.05.016
Gao Y, Baeyens W, De Galan S, Poffijn A, Leermakers M (2010)
Mobility of radium and trace metals in sediments of the
Winterbeek: application of sequential extraction and the DGT tech-
niques. Environ Pollut 158:2439–2445. doi:10.1016/j.envpol.2010.
03.022
Gerringa LJA, de Baar HJW, Nolting RF, Paucot H (2001) The influence
of the salinity on the solubility of Zn and Cd sulphides in the Scheldt
estuary. J of Sea Res 46:201–211. doi:10.1016/S1385-1101(01)
00081-8
Gottesmann W, Kampe A (2007) Zn/Cd ratios in calcsilicate-hosted
sphalerite ores at Tumurtijn-ovoo, Mongolia. Chem Erde 67:323–
328. doi:10.1016/j.chemer.2007.01.002
Gourlay-Francé C, Bressy A, Uher E, Lorgeoux C (2011) Labile, dis-
solved and particulate PAHs and trace metals in wastewater passive
sampling, occurrence, partitioning in treatment plants. Water. Sci
Technol 63(7):1327–33. doi:10.2166/wst.2011.127
Graveline N, Maton L, Luckge H, Rouillard J, Strosser P, Palkaniete K,
Rinaudo J-D, Taverne D, Interwies E (2010) An operational per-
spective on potential uses and constraints of emerging tools for
monitoring water quality. TrAC 29:5. doi:10.1016/j.trac.2010.02.
006
Gurumurthy GP, Balakrishna K, Tripti M, Audry S, Riotte J, Braun JJ,
Udaya Shankar HN (2013) Geochemical behavior of dissolved trace
elements in a monsoon-dominated tropical river basin,
Southwestern India. Environ Sci Pollut Res. doi:10.1007/s11356-
013-2462-7
Han W, Moore AM, Levin J, Zhang B, Arango HG, Curchitser E, Di
Lorenzo E, Gordon AL, Lin J (2009) Seasonal surface ocean circu-
lation and dynamics in the Philippine Archipelago region during
Environ Sci Pollut Res (2015) 22:13842–13857 13855
2004-2008. Dynam Atmos Oceans 47:114–137. doi:10.1016/j.
dynatmoce.2008.10.007
Hatje V, Apte SC, Hales LT, Birch GF (2003) Dissolved trace metal
distribution in Port Jackson estuary (Sydney Harbour), Australia.
Mar Pollut Bull 46:719–730. doi:10.1016/S0025-326X(03)00061-4
Herngren L, Goonetilleke A, Ayoko GA (2005) Understanding heavy
metal and suspended solids relationships in urban stormwater using
simulated rainfall. J Envrion Manag 76:149–158. doi:10.1016/j.
jenvman.2005.01.013
Hestir EL, Schoellhamer DH, Morgan-King T, Ustin SL (2013) A step
decrease in sediment concentration in a highly modified tidal river
delta following the 1983 El Niño floods. Mar Geol 345:304–313.
doi:10.1016/j.margeo.2013.05.008
INAP (2002) Diffusive Gradients in Thin-Films.A technique for
Determining Bioavailable Metal Concentrations. Theory and
Application Literature Surveyhttp://www.inap.com.au/public_
downloads/Research_Projects/Diffusive_Gradients_in_Thin-films.
pdf
Je C, Hayes DF, Kim KS (2007) Simulation of resuspended sediments
resulting from dredging operations by a numerical flocculent trans-
port model.Chemosphere 70:187–195. doi:10.1016/j.chemosphere.
2007.06.033
Jiann KT, Wen LS (2009) Intra-annual variability of distribution patterns
and fluxes of dissolved trace metals in a subtropical estuary
(Danshuei River, Taiwan). J Mar Syst 75:87–99. doi:10.1016/j.
jmarsys.2008.08.002
Ki SJ, Kang JH, Lee SW, Lee YS, Cho YH, An KG, Kim JH (2011)
Advancing assessment and design of storm water monitoring pro-
grams using a self-organizing map: characterization of trace metal
concentration profiles in stormwater runoff. Water Res 45:4183–
4197
Kuehl SA, Nittrouer CA, Allison MA, Faria LEC, Dukat DA, Jaeger JM,
Pacioni TD, Figueiredo AG, Underkoffler EC (1996) Sediment de-
position, accumulation, and seabed dynamics in an energetic fine-
grainedcoastal environment. Cont Shelf Res 5/6:787–815. doi:10.
1016/0278-4343(95)00047-X
Lewis MA, Weber DE, Stanley RS, Moore JC (2001) Dredging impact on
an urbanized Florida bayou: effects on benthos and algal-periphy-
ton. Environ Pollut 115:161–171. doi:10.1016/S0269-7491(01)
00118-X
Li W, Zhao H, Teasdale PR, Wang F (2005) Trace metal speciation mea-
surements in waters by the liquid binding phase DGT device.
Talanta 67(3):571–578. doi:10.1016/j.talanta.2005.03.018
Loo YY, Billa L, Singh A (2014) Effect of climate change on seasonal
monsson in Asia and its impact on the variability of monsoon rain-
fall in Southeast Asia. GSF xxx:1-7. doi:10.1016/j.gsf.2014.02.009
Mackie JA, Natali SM, Levinton JS, Sanudo-Wilhelmy SA (2007)
Declining metal levels at Foundry Cove (Hudson River, New
York): response to localized dredging of contaminated sediments.
Environ Pollut 149:141–148. doi:10.1016/j.envpol.2007.01.010
Masson M, Blanc G, Schäfer J (2006) Geochemical signals and source
contributions to heavy metal (Cd, Zn, Pb, Cu) fluxes into the
Gironde Estuary via its major tributaries. Sci Total Environ 370:
133–146. doi:10.1016/j.scitotenv.2006.06.011
Masson M, Blanc G, Schäfer J, Parlanti E, Le Coustumer P (2011)
Copper addition by organic matter degradation in the freshwater
reaches of a turbid estuary. Sci Total Environ 409(8):1539–1549.
doi:10.1016/j.scitotenv.2011.01.022
Materum R (2010) Physicochemical and particulate characterization of
selected urban-impacted aquatic systems in Manila (The
Philippines) and Bordeaux (France). Rapport de Stage. FDEA.
Université Bordeaux 1
Mazeina LP, Bessonov DU, Bortnikova SB (1999) Zinc and Cadmium
behaviour in tailings. Geochemistry of the Earth’sSurface,
Armannsson (ed.) Balkerna, Rotterdam, ISBN 90 5809 073 6
Meybeck M (2009) Asia-Monsoon Asia. Rivers and Streams.–Gems
Water program UNEP, global river water quality data. http://www.
gemsstat.org/descstats.aspx
Migliavacca D, Teixeira EC, Wiegand F, Machado ACM, Sanchez J
(2005) Atmospheric precipitation and chemical composition of an
urban site, Guaíba hydrographic basin. Brazil Atmos Environ 39:
1829–1844. doi:10.1016/j.atmosenv.2004.12.005
Montero N, Belzunce-Segarra MJ, Gonzalez JL, Larreta J, Franco J
(2012) Evaluation of diffusive gradient in thin films (DGT) as a
monitoring tool for the assessment of the chemical status of transi-
tional waters within the Water Framework Directive. Mar Poll Bull
64:31–39. doi:10.1016/j.marpolbul.2011.10.028
Munk LA, Faure G, Pride DE, Bigham JM (2002) Sorption of trace
metals to an aluminum precipitate in a stream receiving acid rock-
drainage; Snake River, Summit County, Colorado. Appl Geochem
17:421–430. doi:10.1016/S0883-2927(01)00098-1
Nayar S, Goh BPL, Chou LM (2004) Environmental impact of heavy
metals from dredged and resuspended sediments on phytoplankton
and bacteria assessed in in situ mesocosms. Ecotox Environ Safe 59:
349–369. doi:10.1016/j.ecoenv.2003.08.015
Naylor C, Davison W, Motelica-Heino M, Van den Berg GA, Van Der
Heidjt LM (2004) Simultaneous release of sulfide with Fe, Mn. Ni
and Zn in marine harbor sediment measured using a combined
metal/sulfide DGT probe. Sci Total Environ 328:275–286. doi:10.
1016/j.scitotenv.2004.02.008
Neal C, Smith CJ, Jeffrey HA, Harrow M, Neal M (1996) Dissolved
chromium pollution in rainfall and surface waters in mid-Wales
during the mid-1980s. Sci Total Environ 188:2–3. doi:10.1016/
0048-9697(96)05180-7,127-138
Nolting RF, de Baar HJW, Timmermans KR, Bakker K (1999) Chemical
fractionation of zince versus cadmium among other metals nickel,
copper and lead in the northern North Sea. Mar Chem 67:267–287.
doi:10.1016/S0304-4203(99)00076-6
Nyein Aung N, Nakajima F, Furumai H (2008) Trace metal speciation
during dry and wet weatherflows in the Tama River, Japan, by using
diffusive gradients in thin films (DGT). J. Environ.Manage 10:219–
230. doi:10.1039/b709717d
Özsoy T, Örnektekin S (2009) Trace elements in urban and suburban
rainfall, Mersin, Northeastern Mediterranean. Atmos Res 94:203–
219. doi:10.1016/j.atmosres.2009.05.017
Park JH, Inam E, Abdullah MH, Agustiyani D, Duan L, Thuong Hoang
T, Kim KW, Kim SD, Nguyen MN, Pekthong T, Sao V, Sariya A,
Savathvong S, Sthiannopkao S, Syers JK, Wirojanad W (2011)
Implications of rainfall variability for seasonal and climate-
induced risks concerning surface water quality in East Asia. J
Hydrol 400:323–332. doi:10.1016/j.jhydrol.2011.01.050
Pettke T, Oberli F, Audétat A, Guillong M, Simon A, Hanley J, Klemm L
(2012) Recent developments in element concentration and isotope
ratio analysis of individual fluid inclusion by laser ablation, single
and multiple collector ICP-MS. Ore Geol Rev 44:10–38. doi:10.
1016/j.oregeorev.2011.11.001
Pinheiro JP, Domingos RF (2005) Impact of spherical diffusion on labile
trace metals speciation by electrochemical stripping techniques. J
Electroanal Chem 581:167–175. doi:10.1016/j.jelechem.2004.12.
024
Research DGT (2002) DGT-for measurements in water, soils and sedi-
ments. DGT Research Ltd., Lancaster
Schintu M, Marras B, Durante L, Meloni P, Contu A (2010) Macroalgae
and DGT as indicators of available trace metals in marine coastal
waters near a lead-zinc smelter. Environ Monit Assess 167:653–661.
doi:10.1007/s10661-009-1081-8
Shirasago-Germán B, Pérez-Lezama EL, Chávez EA (2015) Influence of
El Niño-Southern Oscillation on the population structure of a sea
lion breeding colony in the Gulf of California. Estuar Coast Shelf
Sci 154:69–76. doi:10.1016/j.ecss.2014.12.024
13856 Environ Sci Pollut Res (2015) 22:13842–13857
Sigg L (2014) 4.15-Metals as water quality parameters-role of speciation
and bioavailability. Reference Module in Earth Systems and
Environmental Sciences. Compr Water Qual Purif 4:315–328. doi:
10.1016/B978-0-12-382182-9.00090-6
Sokolowski A, Wolowicz M, Hummel H (2001) Distribution of dissolved
and labile particulate trace metals in the Overlying bottom water in
the Vistula River Plume (Southern Baltic Sea). Mar Pollut Bulletin
42(10):967–980. doi:10.1016/S0025-326X(01)00069-8
Søndergaard J, Elberling B, Asmund G (2008) Metal speciation and
bioavailability in acid mine drainage from a high Arctic coal mine
waste rock pile: temporal variations assessed through high-
resolution water sampling, geochemical modeling and DGT. Cold
Reg Sci Technol 54:89–96. doi:10.1016/j.coldregions.2008.01.003
Stephens M, Mattey D, Gilbertson DD, Murray-Wallace CV (2008)
Shell-gathering from mangroves and seasonality of the Southeast
Asian Monsoon (Geloina erosa) from the Great Cave of Niah,
Sarawak: methods and reconnaissance of mollusks of early
Holocene and modern times. J Archaeol Sci 35:2686–2697. doi:
10.1016/j.jas.2008.04.025
Takahashi HG (2013) Orographic low-level clouds of Southeast Asia
during the cold surges of the winter monsoon. Atmos Res 131:22–
33. doi:10.1016/j.atmosres.2012.07.005
van den Berg GA, Meijers GG, van der Heijdt LM, Zwolsman JJ (2001)
Dredging-related mobilisation of trace metals: a case study in
The Netherlands. Water Res 35(8):1979–86
vanLoon W, Duffy SJ (2000) Environmental Chemistry: A Global
Perspectives. Oxford University Press Incorporated. ISBN
0198564406, 9780198564409
Varis O, Kummu M, Salmivaara A (2012) Ten major rivers in monsoon
Asia-Pacific: an assessment of vulnerability. Appl Geogr 32:441–
454. doi:10.1016/j.apgeog.2011.05.003
ViersJ, Dupré B, Gaillardet J (2009) Chemical composition of suspended
sediments in World Rivers: new insights from a new database. Sci
Total Environ 407:853–868. doi:10.1016/j.scitotenv.2008.09.053
Villafuerte MQ II, Matsumoto J, Akasaka I, Takahashi HG, Kubota H,
Cinco TA (2014) Long-term trends and variability of rainfall ex-
tremes in the Philippines. Atmos Res 137:1–13. doi:10.1016/j.
atmosres.2013.09.021
Villanueva JD (2013) Suivi par capteurs passifs des polluants émergents
dans les eaux de surface en contexte urbain (Monitoring emerging
pollutants in surface waters using in situ sampling devices in an
urban context), Ph. D. thesis, Université Bordeaux, France
Villanueva JD, Le Coustumer P, Huneau F, Motelica-Heino M, Perez TR,
Materum R, Espaldon MVO, Stoll S (2013) Assessment of trace
metals during episodic events using DGT passive sampler: a pro-
posal for water management enhancement. Water Resour Manag
27(12):4163–4181. doi:10.1007/s11269-013-0401-5
Vuai SAH, Tokuyama A (2011) Trend of trace metals in precipitation
around Okinawa Island, Japan. Atmos Res 99:80–84. doi:10.1016/
j.atmosres.2010.09.010
Vystavna Y, Huneau F, Motellica-Heino M, Le Coustumer P, Vergeles Y,
Stolberg F (2012a) Monitoring and flux determination of trace
metals in rivers of the Seversky Donets basin (Ukraine) using
DGT passive samplers. Environ Earth Sci 65:1715–1725. doi:10.
1007/s12665-011-1151-4
Vystavna Y, Huneau F, Schäfer J, Motellica-Heino M, Blanc G,
Larrose A, Veregeles Y, Dyadin D, Le Coustumer P (2012b)
Distribution of trace elements in waters and sediments of the
Seversky Donets transboundary watershed (Kharkiv region,
Eastern Ukraine). Appl Geochem 27:2077–2087. doi:10.1016/j.
apgeochem.2012.05.006
Weng N, Wang WX (2014) Variations of trace metals in two estuarine
environments with contrasting pollution histories. Sci Total Environ
485–486:604–614. doi:10.1016/j.scitotenv.2014.03.110
Wilkerson FP, Dugdale RC, Marchi A, Collins CA (2002) Hydrography,
nutrients and chlorophyll during El Niño and La Niña 1997-99 win-
ters in the Gulf of the Farallones, California. Progr Oceanogr 54:
293–310. doi:10.1016/S0079-6611(02)00055-1
Witt MLI, Mather TA, Baker AR, De Hoog JCM, Pyle DM (2010)
Atmospheric trace metals over the south-west Indian Ocean: total
gaseous mercury, aerosol trace metal concentrations and lead isotope
ratios. Mar Chem 121:2–16. doi:10.1016/j.marchem.2010.02.005
World Health Organization (2008) Guidelines for drinking-water quality.
Vol. 1 3rd Ed., ISBN 978 92 4 154761 1
Wu Z, He M, Lin C (2011) In situ measurements of concentrations of Cd,
Co, Fe and Mn in estuarine porewater using DGT. Environ Pollut
159:1123–1128
Zhang H, Davison W, Miller S, Tych W (1995) In situ high resolution
measurements of fluxes of Ni, Cu, Fe, and Mn and concentrations of
Zn and Cd in porewaters by DGT. Geochim Cosmochim Acta
59(4192):4181. doi:10.1016/0016-7037(95)00293-9
Zwolsman JJG, Van Eck GTM (1993) Dissolved and particulate trace
metal geochemistry in the Scheldt estuary, S.W. Netherlands (water
column and sediments). Neth J Aquat Ecol 2(4):287–300. doi:10.
1007/BF02334792
Environ Sci Pollut Res (2015) 22:13842–13857 13857
