or part contained in the work will not infringe on the rights of those third parties. The risk of claims resulting from

Overview

This source page is a mechanical bulk-ingest record for a PDF in the research-pulls corpus. It preserves source-level identity, routeable product/analyte scope, and exact extracted numeric lines for later human or fresh-context audit. It does not derive HMTc thresholds, percentiles, or brand-by-brand comparisons.

Key numbers

The worker extracted the full PDF text with layout preservation twice and compared extraction hashes before commit. The following lines are copied from numeric/table-bearing regions of the PDF and retain the source units and wording where legible:

Figure 3.2 Mean Losses in Agricultural Production because of Saline
Table B4.3.1 Environmental Water Quality Index Weights…65
Table B4.5.1 Distortions from the Optimal Nitrogen-to-Phosphorus
nearby buildings or passing ships. The fire of 1969 was not especially notable
1. This is equivalent to 44.3 mg/L as nitrate which is approximately equivalent to the
WHO guideline of 50.0 mg/L as nitrate (corresponding to 11.3 mg/L nitrate-nitrogen).
box 2.5). These multiple dimensions of uncertainty mean that the scale of
Environmental Protection Agency’s prescribed 10 mg/L safety threshold.
little margin of safety” in the 10 mg/L safety limit for nitrates (National
of 10 micrograms per liter (µg/L) (Fraser 2012). The problem of arsenic
10 µg/L 94 percent of the time between 2011 and 2018. In an additional 83
10 µg/L, hospital admissions increase by 30 percent for abdominal pain,
Acute effects are found at the 10 µg/L threshold. As recently as 2001,
the U.S. Environmental Protection Agency (EPA) considered 50 µg/L to
levels of arsenic below 10 µg/L. Moreover, the probability of being employed
10 µg/L (Rodríguez-Lado et al. 2013).
1. 10 mg/L as nitrate-nitrogen (NO3-N), which is approximately equivalent to the WHO
guideline of 50 mg/L as NO3.
1. In Senegal, studies have recorded NO3-N levels beyond 40.0 mg/L, more than four
in Gaza, where NO3 reached concentrations of 500.0 mg/L of NO3 in some areas (10
levels exceeding 100.0 mg/L of NO3 in several regions.
in infants tends to confirm a value near 10 mg/L nitrate as nitrogen as a maximum no-
FIGURE 3.2: Mean Losses in Agricultural Production because of Saline Water, by
(Pérez-González et al. 2012). These problems are not insurmountable, but they call
is 1 mg/L. These thresholds also frequently vary from one regulator to the next or over time.
TABLE B4.3.1: Environmental Water Quality Index Weights
For a 10% increase, nitrogen For a 10% increase, salinity in water
Note: Each panel shows the results from a different regression, described in box 4.4. Error bars show the 95%
growth means an additional 2.5 billion people living in urban areas, with
balanced. An N:P:K ratio of 4:2:1 is generally considered an acceptable benchmark of
reveal the extent of distortion. Table B4.5.1 presents distortions from the optimal N:P
TABLE B4.5.1: Distortions from the Optimal Nitrogen-to-Phosphorus and
United States 79.06 27.04 29.23 92% −32%
of a range of infections.5 A new global study on pharmaceuticals in the
For capital expenditure (CAPEX), costs range from US$34.55 per gram of nitrogen
Note: N = nitrogen; PE60 = 5-day biological oxygen demand per person per day; WW = wastewater;
100,000 PE60, the cost of retrofitting a BNR technology to an existing WWTP ranges
c. A typical BNR effluent after 70 percent nitrogen removal has about 10 to 15 milligrams per liter (mg/L)
of total nitrogen. From that total nitrogen, about 2 mg/L are made up of organic nitrogen, 1 to 5 mg/L
such that WWTPs with such a cost are able to guarantee effluent quality with ≤10 mg/L of NO3-N.
b. Standards are from the World Health Organization (total ammonium < 1.5 milligrams per liter (mg/L)
and BOD < 5 mg/L) and the U.S. Environmental Protection AGency (lead < 15 micrograms (μg)/L,

Methods (brief)

perhaps the largest, database on water quality. Data were collected from
or samples. Satellites collected data from the sky using remote-sensing
several parties can improve the reliability of data collected. These in turn can
increasing reliability with the inclusion of newly collected data.
they are often sparse in space, time, and parameters collected and are often
monitoring stations or collected samples, data from remote sensing, and
parameters collected and the frequency of collection are sporadic across and
collected, which are detailed in the online appendix.
that around a third of growth is lost. When the sample is restricted to
the equator. Local gross domestic product (GDP) data are collected from Kummu, Taka,
have dislodged arsenic deposits and exacerbated water supply contamination (see
characteristics depending on the sample of study. Lastly, to ensure that later-
birth where exposure occurred, the sample is restricted to individuals who
women who were sampled in the DHS data are traced. These birth years range from
solids, or the relative weight of dissolved materials in a sample of water. This is
typically done by collecting a sample of water, evaporating it, and weighing what
meters can calculate EC of a water sample, making it the preferred method.
all three geographic analyses, three samples were created with varying cutoffs for

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

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Verification notes

Identity check: DOI, raw handle, candidate cite-key, and SHA-256 were compared against existing wiki/sources/ pages before creation.
Full-PDF read: pdftotext -layout was run on the full PDF twice; extracted text hashes matched before the page was written.
Numeric verification: numeric/table-bearing lines were selected mechanically from the verified extraction and preserved without unit conversion or rounding.
Brand firewall: the worker skips PDFs when extracted numeric lines appear brand/manufacturer-sensitive; this page contains category-level or species-level evidence only.
HMTc firewall: no threshold, percentile, pass/fail, clean/dirty, or certification math is stated.

Update history

The five most recent substantive edits to this page, classified major (evidence or structure moved), correction (a published value or statement was wrong and has been fixed), or minor (narrative rewritten without changing the underlying evidence). Each description is derived from what the edit did to this page; the linked commit is the authoritative record, routine regeneration passes are excluded, and the full version history lives in git. When DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.

Commit	Date	Change	Description
b01ec52c	2026-08-04	major	2 sections added
d49e450f	2026-08-03	major	5 sections added; narrative text revised